Assignment 2 Prelims

Constant Acceleration

1. An electric vehicle starts from rest and accelerates at a rate of 2.0 m/s2 in a straight line until it reaches a speed of 20 m/s. The vehicle then slows at a constant rate of 1.0 m/s2 until it stops.
(a) How much time elapses from start to stop?
(b) How far does the vehicle travel from start to stop?

2. A world's land speed record was set by Colonel John P. Stapp when in March 1954 he rode a rocket-propelled sled that moved along a track at 1020 km/h. He and the sled were brought to a stop in 1.4 s. In terms of g, what acceleration did he experience while stopping? 1 g = 9.8 m/s2.

Free-Fall Acceleration

3. Raindrops fall 1800 m from a cloud to the ground.
(a) If they were not slowed by air resistance, how fast would the drops be moving when they struck the ground?
(b) Would it be safe to walk outside during a rainstorm?

4. At a construction site a pipe wrench struck the ground with a speed of 24 m/s.
(a) From what height was it inadvertently dropped?
(b) How long was it falling?