Two trains move along the same straight track in the same direction. The first (

Question

Two trains move along the same straight track in the same direction. The first (Train A) has a speed of 32.0 m/s and is following another train (Train B) that has a speed of 15.0 m/s. When the trains are 112 m apart, the conductor of Train A sees the train ahead and applies her brake: so that Train A brakes at a constant rate of 1.00 m/s2.

If the trains collide, the time (s) when this takes place is closest to?

If there is no collision, the distance (m) of closest approach between the two trains is closest to?

Explanation / Answer

Here ,

speed of train 1 , u1 = 32 m/s

speed of train 2 , u2 = 15 m/s

acceleration ,a = - 1 m/s^2

relative speed of train 1 wrt 2 , v = 32- 15

v = 17 m/s

distance , d = 112 m

Now , let the time of collision is t

Using second equation of motion

d = u * t + 0.5 at^2

112 = 17 * t - 0.5 * 1 * t^2

solving for t

t = 8.93 s

the train will collide after 8.93 s

these is collision , hence , the distance of closest appraoch is zero

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.