InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 501. |
Average Speed =Path lengthTime interval |
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Answer» The average speed of an object is defined as the total path length traveled divided by the total time elapsed |
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| 502. |
QuestionAn object of mass 'm'is dropped from a heighth'above the surface of earth. What will be itsvelocity just before reaching the surface ofearth? |
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Answer» please select your questions ok √2gh will be the velocity of the object before reaching the surface of the earth |
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| 503. |
A particle executes simple harmonic motion with an amplitude of 4 cm At the mean position the velocity of the paricle is10 cm/s. The distance of the particle from the mean position when its speed becomes 5 cm/s is(B) 5cm(C) 23)cm(D) 21V5)cm3 cm |
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Answer» As we know in SHM100=16 Omega,hence Omega=100\16(from given value) Now,Again ,5=100/16√A(square)-X(square) Hence X=3.37cm from mean position |
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| 504. |
A particle executes SHM with an amplitude of 4 cm.At the mean position, the velocity of the particle is10 cm/s. The distance of the particle from the meanposition when its speed becomes 5 cm/s is(a) v3 cm(c) 2(/3) crm(b) V5 cm(d) 2(V5) cm |
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Answer» Given, Amplitude , A = 4cm velocity of the particle at mean position , v₀ = 10cm/s We know the relation between speed of particle , amplitude and distance of particle from mean position is given by v = ω√{A² - x²} Here ω is angular frequency, speed at mean position , v₀ = ωA = 10 cm/s speed at x distance from mean position , v = ω√{A² - x²} = 5 cm/s So, ωA/ω√{A² - x²} = 10/5 ⇒ A/√{A² - x²} = 2 ⇒ 4/√(4² - x²) = 2 ⇒ 4 = 4² - x²⇒ x² = 12 ⇒ x = ±2√3 cm Hence, position of particle where speed = 5cm/s is ±2√3 cm |
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| 505. |
monic motion with an amplitude of 4 cm. At the mean position the velocity of the particle is10 cm/s. The distance of the particle from the mean position when its speed becomes 5 cm/s is(B) 5 cm(C) 23)em(D) 246)om |
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| 506. |
(A) 0.10 m/s(B) 0.15 mlscle executes simple harmonic motion with an amplitude of 4 cm. At the mean position the velocity of the particle is10 cm/s. The distance of the particle from the mean position when its speed becomes 5 cm's is(A) 3 cm(B) 5 cm(C) 2(/3) cm |
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| 507. |
20. The escape velocity of a body on the surfaceofthe earth is 11.2 km/s. 1f the earth's massincreases to twice its present value and theradius of the earth becomes half, the escapevelocity becomes:(a) 5.6 km/s(c) 44.8 km/s(b) 11.2 km/s(d) 22.4 km/s |
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Answer» Escape velocity of a projectile from the Earth,vesc= 11.2 km/sProjection velocity of the projectile,vp= 3vescMass of the projectile =mVelocity of the projectile far away from the Earth =vfTotal energy of the projectile on the Earth = (1/2)mvp^2– (1/2)mvesc^2Gravitational potential energy of the projectile far away from the Earth is zero.Total energy of the projectile far away from the Earth = (1/2)mvf^2From the law of conservation of energy, we have(1/2)mvp2– (1/2)mvesc^2 = (1/2)mvf2vf= (vp^2–vesc^2)^1/2= [ (3vesc)^2–vesc^2]^1/2= √8vesc= √8×11.2 = 31.68 km/s. |
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| 508. |
A car moves at a constant speed of 60 km/hr forI km and 40 km/hr for next 1 km. What is theaverage speed of the car? (Ans: 48 km/hr) |
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| 509. |
1) A car moves at a constant speed of 60 km/hr for1 km and 40 km/hr for next 1 km. What is theaverage speed of the car? (Ans : 48 km/hr) |
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| 510. |
L1Q2-2: Average Velocity vs.Average Speed - Part l0.5/3 points (graded)Peter is training for a race. He sprints24 m north in 4s, then walks due southback to his starting position in a time 12s.In the following, take north as the +adirection.Average VelocityAverage SpeedWhat is Peter'saverage velocity ashe sprints?What is Peter'saverage speed as hesprints? |
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Answer» average velocity will be zeroas he returned back to the original position hence the displacement is zero average speed =total distance/total time=24+24/4+12=48/16=3m/sec |
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| 511. |
A ball thrown by one player reaches the other in 2 secthe maximum height attained by the ball above the pointof projection will be about. (a) 10 m(b)7.5 m(d) 2.5 m(c)5 m |
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| 512. |
27. The maximum height attained by a ball projected with speed 20 ms-1 at an angle 45 with the horizontal is[take g 10 ms-2.](1) 40 m(3) 10 m(2) 20 m(4) 30 m |
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Answer» Given, u = 20m/s θ = 45° Maximum height in projectile is given by, h = u²sin²θ/2g = (20)²sin²45°/2*9.8 = 100/9.8 = 10.204 m Thus, maximum height attained by the ball is 10.204 m. |
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| 513. |
9.A 5000 kg rocket is set for vertical firing. Theexhaust speed is 800 ms1. To give an initialupward acceleration of 20 ms-2, the amount ofgas ejected per second to supply the neededthrust will be (g = 10 ms-2)(1) 127.5 kgs-1(3) 185.5 kgs-(2) 187.5 kgs-1(4) 137.5 kgsing with 300 ms- |
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Answer» Mass of rocket(M)= 5000 kg Exhaust speed(v)=800m/s^2 Acceleration(a)=20m/s^2 acceleration due to gravity (g)=10 m/s^2 F=m(g+a)=5000(10+20)=15000N amount of gas ejected per second= F/v=15000/800=187.5 kg/s |
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| 514. |
A man whose mass is 75 kg walks up 10steps, each 20 cm high, in 5s, Find thepower he develops. Take g 10 ms 2. |
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Answer» Power=energy/timeEnergy(j) = work done (j)Hence , power = workdone / timeWorkdone =force[the weight-mg] X distanceWorkdone = 75(10)x(20x10)=150000Thus , power = 150000/5s=30000watts |
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| 515. |
A ball thrown by one player reaches the otherin 2 s. The maximum height attained by theball above the point of projection will be(g 10 ms-2)(1) 2.5 m(3) 7.5 m(2) 5 m(4) 10 m |
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| 516. |
A balloon is going upwards with a velocityof 20 ms ^-1. It releases a packet when it is at aheight of 160 m from the ground. The timetaken by the packet to reach the ground willbe (g 10 ms^-2)1) 6 s3) 8 s2) 10 s4) 12 s |
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| 517. |
The height and width of each step of a staircase are 20cm and 30cm respecively.ball rolls off the top of a stair with horizontal velocity v and hits the fifth step. inemagnitude of v is (g 10 ms)1)1.5 v5. ms ! 2)3/5 ns-1-23) 7.5 ms14) 1.5 ms |
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| 518. |
Example 3.16 The position of an object moving along anx-ax 4t +t, where x is in meters and tin seconds. Find the position of the object at the followingvalues of t (02s, (ii) 4s; (ii) What is the object's displacementbetween t O s and t 4 s?; and (iv) What is its averagevelocity for the time interval from t -2 stot 4 s?is is given by x = 3t |
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Answer» fuck off vghhbbbbbbbbhgffhyffccvhhgfxcvj |
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| 519. |
2. The position of an object moving along x-axis !8.5m, b-2.5 m/s2 andgiven by x-atbt where a-is measured in seconds (a) What is the velocity att=0s and t=2s, (b) what is the average velocitybetween t-2s and t-4s? |
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Answer» X = a + bt^2v = 2bt Velocity at t = 0 is 0Velocity at t = 2s is = 2*2.5*2 = 10 m/s At t = 2sx = 8.5 + 2.5*2^2x = 18.5m At t = 4s x = 8.5 + 2.5*4^2x = 48.5m Average velocity = (48.5 - 18.5) / 2 = 18m/s sis exam point telling the answer sis exam point telling the answer |
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| 520. |
16. Give an example of motion in which averagespeed is not zero, but the average velocity is zero. |
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Answer» When the object travels in a circular path it's average speed is not zero but it's average velocity is zero because it's Displacement will also be zero.. Average velocity = Displacement/time So,the average velocity will also be zero. when any body or an object travels in a circular path it's average speed is not zero but it's average velocity is zero.We know that -Average velocity = Displacement / time So , average velocity will be zero. circular motion in which the average speed is not zero but average velocity is zero |
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| 521. |
Example 3.2 The position of an objectmoving along x axis is given by xa+ bewhere a 8.5 m, b 2.5 m s and t ismeasured in seconds. What is its velocity att 0 s and t- 2.0 s. What is the averagevelocity between t#2.0 s and t 4.0 s ? |
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| 522. |
6. A particle starts S.H.M. from the mean position.Its amplitude is A and time period T. At the timewhen its speed is half of the maximum speed, itsdisplacement y is |
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| 523. |
Example 3.2 The position of an objectmoving along x axis is given by x-a + bt2where a 8.5 m, b 2.5 m s2 and t ismeasured in seconds. What is its velocity att 0 s and t 2.0 s. What is the averagevelocity between t-2.Os and t 4.0 s ? |
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Answer» X = a + bt^2v = 2bt Velocity at t = 0 is 0Velocity at t = 2s is = 2*2.5*2 = 10 m/s At t = 2sx = 8.5 + 2.5*2^2x = 18.5m At t = 4s x = 8.5 + 2.5*4^2x = 48.5m Average velocity = (48.5 - 18.5) / 2 = 18m/s |
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| 524. |
Example 3.2The position of an objectmoving along x axis is given by xs a + btwhere a#8,5 m, b 2.5 m s-2 and t ismeasured in seconds. What is its velocity at1-0 s and t 2.0 s. what is, the averagevelocity between t # 2.0 s and t 4.0 s ? |
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| 525. |
Explain the terms:i) Uniform Velocityii) Average Velocityiii) Instantaneous Velocity) |
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Answer» A body os said to have uniform velocity if it covers equal distance in equal interval of time in a particular direction, however the time intervals may be small.This means that if a body is travelling at a constant speed along a straight line then it is said to have uniform velocity. i)A body is said to haveuniform velocityif it covers equal distance in equal intervals of time in a particular direction, however the time intervals may be small. Thismeansthat if a body is traveling at a constant speed along a straight line (i.e, a particular direction) then it said to haveuniform velocity. ii)Theaverage velocity can bedefinedas the displacement divided by the time. iii)Instantaneous velocityis thevelocityof an object in motion at a specific point in time. This is determined similarly to averagevelocity, but we narrow the period of time so that it approaches zero. If an object has a standardvelocityover a period of time, its average andinstantaneous velocitiesmay be the same. |
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| 526. |
2 A car runs at constant speed on a circular track of radius 100 m taking 62.8 s on each lap.Whatistheaverage speed and average velocity on each complete lap?(1) velocity 10m/s, speed 10 m/s(3) velocity zero, speed zero(2) velocity zero, speed 10 m/s(4) velocity 10 m/s, speed zero |
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Answer» Write S'l unit of speed and velocity define resultant velocity |
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| 527. |
es the ground.*S/ Explain the terms âaverage velocity, and instantaneous velocity, when are they equal? |
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Answer» The average velocity of an object is its total displacement divided by the total time taken. In other words, it is the rate at which an object changes its position from one place to another. Average velocity is a Vector quantity. The SI unit is meters per second. Instantaneous velocity is defined as the rate of change of position for a time interval which is very small (almost zero). Average velocity is equal to the instantaneous velocity when acceleration is zero. In order for acceleration of an object to equal zero, there can be no change in speed or direction. For example, when a car is traveling down a straight road on flat land using cruise control. |
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| 528. |
1. A body describes the first half of the total 1distance with velocity v, and the secondhalf with velocity v2. The averagevelocity is: |
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Answer» Let assume the distance be 2X. By the question , AVERAGE VELOCITY (V)= TOTAL DISPLACEMENT / TIME TAKEN Total displacement = 2X Have to find time taken for the V1 and V2. time taken for the first half = X/V1 time taken for the next half = X/V2. substitute value in AVERAGE VELOCITY V =2S/(X/V1 + X/V2) take "x" common and take L.C.M V= 2S /X( V1 + V2 )/V1 V2 V= 2S (V1 V2)/ X (V1 + V2). |
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| 529. |
what is the formula to find1. speed2. Velocity3. distance4. displacement5. time period6. average speed7. average velocity8. magnitude9. momentum10. relative density11. density |
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| 530. |
A person travels along a straight road for half the distance withvelocity vi and the remaining half distance with velocity v2 Theaverage velocity is given by [MP PMT 2001] |
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Answer» Let Let T be the time taken by the person to cover complete distance. Case I:let x1 be the half distance covered. speed=v1time taken to cover the first half of the journey :t1=distance/speed=(x/2)/v1 Case IIlet x2 be the half distance covered.speed=v2time taken to cover the second half of the journey :t2=distance/speed=(x/2)/v2 Total time=T=t1+t2=x/(2v1)+x/(2v2) T=x/2[1/v1+1/v2] =x[v1+v2]/2v1v2 Average Velocity= Displacement/ total time=x/x[v1+v2]/2v1v2=2v1v2/(v1+v2) ∴Average velocity is given by 2v1v2/(v1+v2) you are correct i was just testing the app but brainly is much better than this app |
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| 531. |
Example 2.15 Let us consider an equation2here m is the mass of the body, u itslocity, g is the acceleration due toavity and h is the height. Checkhether this equation is dimensionallyrect |
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Answer» Here we have to check the dimensions of 1/2(m)v² and mgh foe 1/2mv² the dimension is M(L/T)² = ML²T-² now for mgh , the dimension is M(L/T²)L = ML²T-². so we can say that the equation is dimensionally correct |
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| 532. |
11. (a) Induced e.mf, depends on rate of change of linkedb) Induced e.m.f,(A) a- true(C) both - truedirection opp. to e.mf. applied.(B) b- true(D) both false |
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Answer» ..Induced EMF= (change in Magnetic Flux Density x Area)/change in Time.induces emf is opposite to the emf appliedhenceoption b |
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| 533. |
340 m sA sound wave travels at a speed of 339 m s,is 1.5 cm, what is the frequency of the wave? Wille audible |
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| 534. |
heard at the 10340 m s4 A sound wave travels at a speed of 339 m s1. If itsof the wave? Will it be audible?is 1.5cm, what is the frequency |
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| 535. |
03]Example 24. Two buses A and B are at positions 50 m and100 m from the origin at time t 0. They start moving in thesame direction simultaneously with uniform velocity of10 ms 1 and 5 ms . Determine the time and position atwhich A overtakes B. |
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Answer» Let the time at which the Bus A overtakes the bus B be T seconds. ∴ Distance travelled by the Bus A from the Origin in Time T = Speed× Time= 10× T= 10 TTotal Distance of Bus A = 50 + 10T Now,Distance travelled by the Bus B in time T seconds = 5× T= 5TTotal Distance of Bus B = 100 + 5T We know,Distance of Bus A after T seconds = Distance of the Bus B after T seconds. ⇒ 50 + 10T = 100 + 5T⇒ 10T - 5T = 100 - 50⇒ 5T = 50⇒ T = 50/5⇒ T = 10 seconds. Time at which the Bus A overtake the Bus B is 10 seconds. Now, Total Distance travelled by the Bus A from the origin = 50 + 10T= 50 + 10(10)= 50 + 100=150 m. ∴ Distance from the origin at which the Bus A overtake the Bus B is 150 m. |
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| 536. |
A body is thrown at an angle 30° to the horizontal with the velocity of 30 m/s. After 1 sec,velocity will be (in m/s) (g 10 m/s)A) 107(B) 700 /10(C) 1007(D)/T0 |
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Answer» Along vertical = v = u + at= vSinθ’ = uSinθ - gt= v Sin 30 = 30 * u Sin 30 + 1 * 10= v * 1/2 = 30 * 1/2 + 10= v / 2 = 25= v = 5 m/s. |
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| 537. |
70. A wave has a velocity u in medium P and velocity 2u inmedium Q. If the wave is incident in medium P at an angle30°, then the angle of refraction will be(a) 30° (b) 45° (c) 600 (d) 90 |
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| 538. |
A body is thrown at an angle 30° to the horizontal with the velocity of 30 m/s. After 1 sec, itsvelocity will be (in m/s) (gA) 10 73.010 m/s?)(B) 700 /10(C) 100/7(D) 10 |
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| 539. |
An electric train is moving with a velocity of 30 m/s. How much ditance will it travel in 30 s |
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Answer» distance travelled = velocity× time = 30*30 = 900m |
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| 540. |
21. A car starts with velocity 10 m's and scalerates at rate 5 m/s? Find the finalvelocity when the car has travelled a distar ca 30 m |
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Answer» Using relation Vf - Vi = atVf - 10 = 5 * tt = (Vf - 10)/5 Now,S = Vi*t + 1/2 at^230 = 10*(Vf - 10)/5 + 1/2*5*[(Vf-10)/5]^2 30 = 2Vf - 20 + 5/2 *(Vf - 10)^2/25 30 = 2Vf - 20 + 5/2(Vf^2 + 100 - 20Vf)/25 30 = 2Vf - 20 + 1/10(Vf^2 + 100 - 20Vf) 50*10 = 20Vf + Vf^2 + 100 - 20Vf Vf^2 = 500 - 100 = 400 Vf = 20 Therefore,Final Velocity = 20 m/s |
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| 541. |
A particle is thrown from the top of abuilding of height 50 m with a velocity 30m/s at an angle of 30° with the horizontal.The distance of the base of building to thepoint where the particle hits the ground is(A) 100 rm(C) 120 m(B) 110 m(D) 130 m. |
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| 542. |
The minimum deviation produced by a glass prismhaving an angle of 60° is 30. if the velocity of light inair is 3 x108 ms1, calculate its velocity in glass. |
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| 543. |
The value of i in the following circuit diagram will be8 V3040303234(2) A(3) A(4) 1 A2 |
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Answer» thanks a bunchby the way are you really a grade 8 student? |
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| 544. |
A sound wave has afrequency of 2 kHz and wave length35 cm. How long will it take to travel1.5 km? |
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Answer» F= 2000hzw.l. = .35m speed = f × w.l.700m/s now dist. = 1500 mtime= d/sp.1500/70015/7s2.142sec. |
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| 545. |
Ryan while verifying the laws of reflection of sound measured the anglebetween the incident sound wave & reflected sound wave to be 1300.What is the angle of incidence? Draw the diagram showing inci dentsound wave, reflected sound wave and the angle of incidence. |
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Answer» Since the normal makes an angle of 90 with the plain.Therefore,Let angle between incident ray and plain be X.=> angle of incidence=(90-X)=> angle of refraction=(90-X)According to question:90-x+ 90-x=130=>180-2x=130=>2x=50=x=25. |
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| 546. |
A sound wave has a frequency of 4 kHz and a wavelength of 40 cm. The time taken by thesound wave to travel a distance of 3.2 km is:IS: |
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Answer» Here we are given the frequency as 4 kHz We know that 1 kHz = 1000 Hz So , 4kHz = 4000 Hz Frequency, f = 4000 Hz Also , Wavelength , λ = 40 cm 1 cm = 0.01 metres So , Wavelength , λ = 0.40 metres We know that 1 kilometre = 1000 metres So ,3.2 kilometre = 3200 metres We know that ,Velocity = frequency x Wavelength = 4000 x 0.40 = 1600 m/s Also , Time = Distance/Velocity = 3200 / 1600 = 2 s |
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| 547. |
6. What do you mean by rolling friction? |
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Answer» The opposing force experienced when one surface rolls over the other is called rolling friction. rolling frictionorrollingdrag,isthe force resisting the motion when a body (such as a ball, tire, or wheel) rolls on a surface. . Rolling friction is the force of resistance by the opposite objects. |
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| 548. |
state the meaning of the term rolling friction |
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| 549. |
Maximum value of static friction is1) Limiting friction 2) rolling friction3) static friction4) normal reaction |
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Answer» 1 limiting friction .... when it got equals to sign .... limiting friction... you got to have a better concentration on the graph... you can very well see that limiting friction will have the peak while other don't. Limiting friction is the maximum value of static friction. limiting friction is the max value of static friction. 1) limiting friction 1)'' Limiting friction'' the maximum value of static friction.So, option 1st is correct answer. the maximum friction of static friction is limiting friction limiting friction is right answer the option 1st is right maximum value of static friction is limiting friction limiting friction has the max. value limiting friction is the answet limiting friction is the maximum value of static friction 1) limiting friction is the max value of static friction therefore the correct answer is the limiting friction |
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| 550. |
Explain why sliding friction is less than static friction. |
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Answer» Thesliding friction is less than static frictionbecause of the interlocking of irregularities in the two surfaces. When the object startsslidingthe contact points on its surface, do not get enough time to lock into the contact points on the floor. So thesliding frictionis slightlyless thanthestatic friction. |
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