Chapter 2, Problem 51P

In the vertical jump, an athlete starts from a crouch and jumps upward to reach as high as possible. Even the best athletes spend little more than 1.00 s in the air (their "hang time"). Treat the athlete as a particle and let ymax be his maximum height above the floor.To explain why he seems to hang in the air, calculate the ratio of the time he is above ymax/2 (moving up from ymax/2 to ymax and then moving down to ymax/2) to the time it takes him to go from the floor to that height. You may ignore air resistance.

A Physics student did daredevil stunt by bailing out and falling freely 50 meters.His parachute opens and thereafter he decelerates at 2 m/s2. He reaches theground with a speed of 3m/s. Find the time it takes the parachutist to reach the ground and what height did the fall begin?

A bush baby can leap straight up to a height of 2.1 m off the ground. To reach this height, with what speed would it need to leave the ground, in m/s? Use g = 9.8 m/s2.

A helicopter is ascending vertically with a speed of 5.30 m/s. At a height of 107 m above the Earth, a package is dropped from the helicopter. How much time does it take for the package to reach the ground? [Hint: What is v0 for the package?] Express your answer to three significant figures and include the appropriate units.   My Answer is that t= 4.163 but what unit is it? I tried s, m/s, min but none of them were correct. PLEASE HELP CONFIRM MY ANSWER and THE UNIT along with 4.163

Superman starting from rest has an acceleration of 10m/s2 up. He makes it 127m into theair before he’s exposed to kryptonite and is only under the influence of gravity.(a) How long after take off is Superman exposed to kryptonite?(b) What is Superman’s velocity when he is exposed to the kryptonite?(c) What is the maximum height Superman reaches?(d) What is the total amount of time Superman is in the air?

In the vertical jump, an Kobe Bryant starts from a crouch and jumps upward to reach as high as possible. Even the best athletes spend little more than 1.00 ss in the air (their "hang time"). Treat Kobe as a particle and let ymaxymax be his maximum height above the floor. Note: this isn't the entire story since Kobe can twist and curl up in the air, but then we can no longer treat him as a particle.   Hint:  Find v0 to reach y_max in terms of g and y_max and recall the velocity at y_max is zero.  Then find v1 to reach y_max/2 with the same kinematic equation.  The time to reach y_max is obtained from v0=g (t), and the time to reach y_max/2  is given by  v1-v0= -g(t1).  Now, t1 is the time to reach y_max/2, and the quantity t-t1 is the time to go from y_max/2 to y_max.  You want the ratio of (t-t1)/t1   To explain why he seems to hang in the air, calculate the ratio of the time he is above ymax/2ymax/2 moving up to the time it takes him to go from the floor to that height. You may ignore…

A kangaroo leaps upward at time t = 0. At time t = 1.0 s it is at a height of 2.0 m above the ground. At what time does it reach its maximum height? Express your answer in seconds. (Assume proximity to the Earth's surface and neglect friction).

A man from his window, from the building where he lives, throws a ball vertically upwards with a speed of 6[m/s]. Notice that it takes three seconds for the ball to climb and down to the ground. Suppose the maximum height the ball reaches is the roof of the building. What is the height of the building?

Answer this problem step by step. A golf ball is thrown downward at a speed of 10 m/s. If its velocity just before it hits the ground is 5.6 m/s, from what height was it thrown? 1. Answer the problem step by step.