Car B is traveling a distanced ahead of car A. Both cars are traveling at 60 ft/s when the driver of B suddenly applies the brakes, causing his car to decelerate at 17 f/s. It takes the driver of car A 0.75 s to react (this is the normal reaction time for drivers). When he applies his brakes, he decelerates at 20 ft/s. Determine the minimum distance d between the cars so as to avoid a collision. (Ctrl) -

A typical jetliner lands at a speed of 160 mi/h and decelerates at the rate of (10.0 mi/h)/s. If the plane travels at a constant speed of 160 mi/h for 1.00 s after landing before applying the brakes, what is the total displacement of the aircraft between touchdown on the runway and coming to rest?

As two trains move along a track, their conductors suddenly notice that they are headed toward each other. The figure gives their velocities v as a function of time t as the conductors slow the trains. The figure's vertical scaling is set by vs = 21 m/s.The slowing process begins when the trains are 164.00 m apart. What is their separation when both trains have stopped?

Alice and Bob are racing each other in the Tour de France bicycle race. At time t = 0, Alice and Bob are next to each other bicycling in the same direction. Alice moves with an initial velocity of 12 m/s, speeding up at a rate of 0.8 m/s?. Bob has an initial velocity of 17 m/s and is slowing down at a rate of 0.5 m/s?. (a) When will Alice and Bob next be tied? (b) How far will they have traveled in that time?

A hockey player is standing on his skates on a frozen pond when an opposing player, moving with a uniform speed of 12 m/s, skates by with the puck. After 3.0s, the first player makes up his mind to chase his opponent. If he accelerates uniformly at 4.0 m/s, how long does it take him to catch his opponent?

While moving from her third-storey apartment, a university student decides to lower her couch through her window using ropes. During the process, the ropes snap and the couch, which is 12.0 m above the ground, falls to the ground below. Her friends, who are both 1.50 m tall, notice the accident when the couch is directly above them. Determine the time they have to get out of the way.

A demonstration of reaction time is to hold one end of a dollar bill so that it hangs lengthwise below your fingers, then ask a friend to hold his fingers near the lower corner of the bill. When you release the bill, he is to try to catch it. If a typical reaction time in this case is 0.25 s, how long would a bill need to be for a person to have a good chance of catching it?

Consider a grey squirrel falling from a tree to the ground. Use a coordinate system in which positive is downward for this problem. a) Find the squirrel’s velocity, in meters per second, just before hitting the ground when it falls from a height of 1.3 m. Ignore air resistance.  b) The squirrel softens its landing by bending its legs when it touches the ground, thereby stopping itself over a distance of 7.6 cm. Assuming a constant rate of deceleration, find the squirrel’s acceleration during this process, in meters per second squared.

Nerve impulses travel at different speeds, depending on the type of fiber through which they move. In a scenario, the impulses for touch traveled at 57.3 m/s, while those registering for pain moved at 0.82 m/s. If a person stubs his toe, find the time delay between the pain and touch impulses. Assume that his brain is 1.60 m from his toe and that the impulse travels directly from toe to brain. Express your answer in seconds.   Hint: Always take the positive value. Time difference is synonymous to time delay.

A model rocket is launched from the ground at rest. The acceleration of the rocket is ?⃗ = 90 ?̂ ? ? 2 . After 1.5 seconds, the rocket fuel is expended, and the acceleration of the rocket returns to ?⃗ = −9.8 ?̂ ? ? 2 . a) Find the velocity of the rocket just as the fuel is expended (Answer: 135?̂ ? ? ) b) Find the height of the rocket just as the fuel is expended (Answer: 101?̂ ?) c) How long does it take the rocket to reach maximum height after the fuel is expended? (Answer: 13.8 ?) d) What is the maximum height of the rocket? (Answer: 1031 ?) e) What is the impact velocity of the rocket as it hits the ground? (Answer: −142?̂ ? �