Question

A bicycle racer sprints at the end of a race to clinch a victory. The racer has an initial velocity of 11.2 m/s and accelerates at the rate of 0.3 m/s2 for 6.9 s.

a)The racer continues at this velocity to the finish line. If he was 293 m from the finish line when he started to accelerate, how much time did he save (in s)?

b)One other racer was 5 m ahead when the winner started to accelerate, but he was unable to accelerate, and traveled at 11.5 m/s until the finish line. How far ahead of him (in seconds) did the winner finish?

c) How far ahead of him (in meters) did the winner finish?

A fast elevator in a skyscraper is employing the following scheme to get from the starting level to the desired level: For the first half of the time it accelerates at the maximum allowed acceleration of 1.0 m/s2 and for the second half it decelerates at the maximum allowed acceleration of −1.0 m/s2. How long does it take (in seconds) to go from ground level to the highest level at 80 m elevation?

A track team is practicing for a 4 × 100 m relay race. The first runner, Linda, is running at a constant speed of 8.6 m/s. The next runner, Jenny, will be starting from rest at the 80 m mark. She has an acceleration of 1.0 m/s2. Ideally the two runners meet at the 100 m mark to hand over the baton. At this point, Jenny is still accelerating.

a) How long does it take Jenny to run from the 80-m mark to the 100-m mark?

b) At what distance behind Jenny should Linda be when Jenny starts running? (Assume for simplicity that there is no distance between the two runners when the switch happens.)

c) What’s Jenny’s speed at the 100m mark?

Answer 1