LAUNCHPADA 100 m long train is moving with a uniformelocity of 45 km/h

1.	LAUNCHPADA 100 m long train is moving with a uniformelocity of 45 km/hr. The time taken by thain to cross a bridge of length 1 km is58 s (b) 68 s (c) 78 s ) 88 s
Answer» The formula for velocity is distance ÷ time taken. In symbols: V=S÷t. Where: V = velocity S = distance t = time taken. To solve your question: You need to convert each unit to its standard form, so: V = 45Km/hr = 12.5m/s S = 1km = 1000m t = ? Solution V = S÷t 12.5 = 1000÷t Making t subject of formula: t = 1000÷ 12.5 t = 80 seconds. So it will take 80 seconds for a train moving at 12.5 meters every second to cross a kilometer long bridge. However, The question states the train is 100 meters long. This means the last point on the train has an extra 100 meters to cover. So it becomes: t = 1100 ÷12.5 t = 88 seconds. So the time it takes a train 100m long, moving at 12.5km/hr to cover 1km is 88 seconds or 1 minute, 28 seconds

LAUNCHPADA 100 m long train is moving with a uniformelocity of 45 km/hr. The time taken by thain to cross a bridge of length 1 km is58 s (b) 68 s (c) 78 s ) 88 s

Answer»

The formula for velocity is distance ÷ time taken. In symbols:

V=S÷t.

Where:

V = velocity

S = distance

t = time taken.

To solve your question:

You need to convert each unit to its standard form, so:

V = 45Km/hr = 12.5m/s

S = 1km = 1000m

t = ?

Solution

V = S÷t

12.5 = 1000÷t

Making t subject of formula:

t = 1000÷ 12.5

t = 80 seconds.

So it will take 80 seconds for a train moving at 12.5 meters every second to cross a kilometer long bridge.

However,

The question states the train is 100 meters long.

This means the last point on the train has an extra 100 meters to cover.

So it becomes:

t = 1100 ÷12.5

t = 88 seconds.

So the time it takes a train 100m long, moving at 12.5km/hr to cover 1km is 88 seconds or 1 minute, 28 seconds

Discussion

No Comment Found

Related InterviewSolutions

7. A body has a weight 50 N in air. Afterimmersing completely in liquid its weight is20 N. Then, the buoyant force on the bodywill be
Name the particulate which causes the disease mentioned below:(a)minamata (b)silicosis.
- Where does a body weight more at the surface of the carth or in a mine?
DelyAbody79entire chainthe ch.57. A body of mass 50gm collides elastically with anotherbody of mass 30 gm at rest. Then the percentage lossof the velocity of the colliding body during collision is1) 25% 2) 75% 3) 50% 4) 67%3) 120380.beide
What will be the acceleration of a body of mass5 kg if a force of 200 N is applied on it?
Rig. 5.168.13 Two bodles of masses 10 kg and 20 kg respectively kept on a smooth, hortzontalsurface are tied to the ends of a light string a horizontal force F 600 Nsapplied to lu A (t) B along the direction of string. What is the tension in thestring in each case
culate the gravitational force befween two protons kept at a distance67 x 10-27 kg. (1 femtometre = 10-15 m)
15. A uniform chain of length 2 m is kept on atable such that a length of 60 cm hangs freelyfrom the edge of the table. The total mass ofthe chain is 4 kg. What is the work done inpulling the entire chain onto the table ?(g = 10 m/s)1) 7.2J273.63) 120J4) 1200
Two block of mass 3 kg and 6 kg respectively are placed on a smooth 1.0 m/shorizontal surface. They are connected by a light spring of force 3 kgconstant k 200 N/m. Initially the spring is unstretched. The indicatedzmvelocities are imparted to the blocks. The maximum extension of thespring will be:A30 cm(C) 20 cm2.0 mls(B) 25 cm(D) 15 cm
88. A piece of stone is thrown vertically upwards. It reaches the maximum height in 3 seconds. If the accelerationof the stone be 9.8 m/s directed towards the ground, calculate the initial velocity of the stone with which itis thrown upwards.