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U = 0 s = 400 mt = 20 secondm = 7 ✖ 1000 = 7,000 kg. (1 tonne = 1,000kg )a =?F=?soos = ut +1/2 at square put given numbers400=0+1/2 a(20)square=400/200=2 m/s square ........now F = m ✖ a = 7,000 ✖ 2= 14,000 N

If a number of vectors are represented, in magnitude and direction, by the sides of incomplete polygon taken in order, then their resultant is denoted by the closing side of the polygon in magnitude and direction, taken in opposite order.

Here is a similar question. Kindly follow the methodology.

Answer:3)MetalsExplanation:Conductors thatobey Ohm's law aremade ofmetal, carbon and some alloys.

ohms law is obey by only those material which allows current to pass through it i.e conductors and they are made up of metals 3 =metals

Newton's third law of motion is applicable to the gravitational force existing between the various objects in the universe.According to Newton's third law of motion “to every action, there is an equal and opposite reaction”. That is, if a body A exerts a force on another body B, then the body 'B' also exerts an equal and opposite force on the body 'A'.

Two bodies A and B exerts an equal and oppositeforce on each otherFor example, Let us consider the gravitational force existing between a stone and the Earth. What do you observe when a stone is dropped from a height? It falls towards the Earth. This is because the Earth exerts a force on the stone and according to the universal law of gravitation, the stone also exerts an equal force on the Earth.

Newton's laws of motion are three physical laws that, together, laid the foundation for classical mechanics. They describe the relationship between a body and the forces acting upon it, and its motion in response to those forces

Mass of body A, ma= 150 g = 0.15 kg

Mass of body B, mb= 250 g = 0.25 kg

Both the bodies are moving towards each other. Let the direction of B be taken as positive. Then the direction of A will be considered negative.

Velocity of A, va= - 3 m/s

Velocity of B, vb= 3 m/s

Now, total momentum of the system,

P = mava+ mbvb

=> P = (0.15)(-3) + (0.25)(3)

=> P = -0.45 + 0.75

=> P = 0.30 Ns

slope depicts acceleration

The VT graph

Let the dist be 2x1st halfdist =xspeed is 6m/ss=d/tt=d/s=x/6

2nd halfdist xspeed is 3m/stime =d/s=x/3

average speed=total dist /total time=x+x/(x/6)+(x/3)=2x/3x/6=2x*6/3x=4m/s

The answer is Option 1.

1. The Law of Orbits: All planets move in elliptical orbits, with the sun at one focus.

2. The Law of Areas: A line that connects a planet to the sun sweeps out equal areas in equal times.

3. The Law of Periods: The square of the period of any planet is proportional to the cube of the semimajor axis of its orbit.

11j (option d ) is right answer

Energy in the state of rest, E1 = 3 J

KEat mean position, E2 = 2 x Mean KE = 2 x 4 = 8 J

Total energy, Et = E1 + E2 = 3 + 8 =11 J

Option 4)11 J is correct as:-Energy in the state of rest, E1 = 3 J

KEat mean position, E2 = 2 x Mean KE = 2 x 4 = 8 J

Total energy, Et = E1 + E2 = 3 + 8 =11 J

can you solve the integration steps

(a) option is correct

dv = dx/dtdv = d(6-4t + 6t^2)dv = 12t -4

now, equating this to the equation y= mx +cdv= 12t + (-4)

since the y intercept is negative only in 1st option, we conclude that it is the right ans.

Particle is moving along x-axis so displacement is also along x-axis

Now , ⇒ x = 6t²-5t+2

since , V = dx/dt

Differentiating w.r.t. 't'

⇒ v = 6 × 2t - 5

⇒ v = 12t - 5

Hence initial velocity

v = 0-5 = -5 m/sec

Torquehasdimensionforce times distance, symbolically L2MT−2.

(i) It states that for a body falling freely the total mechanical energy remains conserved.(ii) Suppose a ball of mass ‘m’ falls under the effect of gravity as shown in figure.Let us find the kinetic and the potential energy of the ball at various points of its free fall. Let the ball fall from point A at a height h above the surface of the earth.At Point A:At point A, the ball is stationary; therefore, its velocity is zero.Therefore, kinetic energy, T = 0 and potential energy, U = mghHence, total mechanical energy at point A isE = T + U = 0 + mgh = mgh… (i)At Point B :Suppose the ball covers a distance x when it moves from A to B. Let v be the velocity of the ball point B. Then by the equation of motion v^2-u^2 = 2aS, we havev^2 - 0 = 2gx or v^2 = 2gx Therefore,Kinetic energy, T = 1/2 mv^2 = 1/2 x m x (2gx)= mgxAnd Potential energy, U = mg (h - x)Hence, total energy at point B isE = T + U = mgx + mg(h-x) = mgh …(ii)At Point C :Suppose the ball covers a distance h when it moves from A to C. Let V be the velocity of the ball at point C just before it touches the ground. Then by the equation of motion v^2 - u^2 = 2aS, we have V^2 - 0 = 2gh or V^2 = 2gh.Therefore,Kinetic energy,T = 1/2 mV^2 = 1/2 x m x (2gh) = mghand Potential energy, U = 0Hence, total energy at point E = T + U= mgh + 0 = mgh… (iii)Thus, it is clear from equations (i), (ii) and (iii), that the total mechanical energy of a freely falling ball remains constant.

since the speed is constantbut velocity is changing so it is in accelerated motion , option A.

Theformulathat describes refraction is also known asSnell's Law. The angle of refraction depends on the angle of incidence of the light, and the indexes of refraction of the two materials. ... As a reminder, the angles inSnell's Laware always measured relative to the normal (perpendicular) to the surface.

Snell's law(also known asSnell–Descartes lawand thelaw of refraction) is aformulaused to describe the relationship between theangles of incidenceandrefraction, when referring to light or otherwavespassing through a boundary between two differentisotropicmedia, such as water, glass, or air.

In optics, the law is used inray tracingto compute the angles of incidence or refraction, and in experimental optics to find therefractive indexof a material. The law is also satisfied inmetamaterials, which allow light to be bent "backward" at a negative angle of refraction with anegative refractive index.

Snell's law states that the ratio of thesinesof the angles of incidence and refraction is equivalent to the ratio ofphase velocitiesin the two media, or equivalent to the reciprocal of the ratio of theindices of refraction:

{\displaystyle {\frac {\sin \theta _{2}}{\sin \theta _{1}}}={\frac {v_{2}}{v_{1}}}={\frac {n_{1}}{n_{2}}}}

with each{\displaystyle \theta }as the angle measured from the normal of the boundary,{\displaystyle v}as the velocity of light in the respective medium (SI units are meters per second, or m/s),{\displaystyle \lambda }as the wavelength of light in the respective medium and{\displaystyle n}as the refractive index (which is unitless) of the respective medium.

The law follows fromFermat'sprinciple of least time, which in turn follows from the propagation of light as waves.

sin i /sin r =constant

sini/sinr =constant is the correct answer of the given question is

A free body diagram is a sketch of an object of interest with all the surrounding objects stripped away and all of the forces acting on the body

by spitting or sneezing

how we can say that??

The block leave contact where the normal reaction is zero so mv²/r = mgcosθ and v² = u²+2as so v² = 1/4gr + 2gr(1-cosθ) so 1/4 + 2(1-cosθ) = cosθ so 3cosθ = 9/4 so cosθ = 3/4 and θ = cos-¹(3/4).

these don't seem to be class 10 questions

unable to understand

can understand them perfectly

means

how you write v²

I will give questions which you will be solving for years

yes

now your grade is correct

a) is the correct answer

c) is the correct answer

On a frictionless surface, you would only be able to jump straight up. Any force applied parallel to the surface would cause you to slip as there is no friction to push against you and keep you from falling over. You can never make any sideways movement when all you can do is move up and down (and fall over).

What you could do is lie on one's back and take a deep breath, then stand up (a very dificult jump indeed under frictionless conditions) and jump into the air. When one is in the air, blow out the air you previously took in...causing you to accelerate in the opposite direction. When you land, since there is no frictionl you will keep that motion and continue to slide.

If the velocity of an object varies with time, it is called an accelerated motion.If the change in velocity is uniform, it is a called uniformly accelerated motion.Examples:1) The motion of a freely falling body and a vertically thrown up body is an example of uniform acceleration. 2) The motion of a ball rolling down an inclined plane is another example of uniform acceleration.

An electric current is a flow of electric charge. SI unit - Ampere (A)

from the first equation of motion, V = U + AT

Therfore, V - U = AT

We know that, S = (U + V / 2 )×T ∴ S/T = U + V / 2 ∴U + V = 2×S/T ∴ U + V = 2S / TSo Substituting eq1 and eq2, (V - U ) (V + U ) = AT ×2S/T ∴V² - U² = 2AS.

acceleration (a) = rate of change in velocity (or) change in velocity per unit time = change in velocity/time …………………………………..eq(1)

Let us assume the initial velocity to be ‘u' and final velocity be ‘v' and the taken to attain the final velocity from the initial be ‘t'

Therefore, change in velocity = v-u

Now equation (1) becomes,

→a=(v-u )/t

→at=v-u

And therefore, v=u+at

Using,s = ut + 1/2 at^25 = 1*2 + 1/2 * a * (2)^25 = 2 + 2a2a = 3a = 3/2 m/s^2

Now,Using v = u + atv = final velocity

v = 1 + 3/2 * 2v = 1 + 3 = 4 m/s

(c) is correct option

78m is correct answer