Review. A force platform is a tool used to analyze the performance of athletes by measuring the vertical force the athlete exerts on the ground as a function of time. Starting from rest, a 65.0-kg athlete jumps down onto the platform from a height of 0.600 m. While she is in contact with the platform during the time interval 0< t < 0.800 s, the force she exerts on it is described by the function F = 9 200t – 11 500 t 2 where F is in newtons and t is in seconds. (a) What impulse did the athlete receive from the platform? (b) With what speed did she reach the platform? (c) With what speed did she leave it? (d) To what height did she jump upon leaving the platform?
Review. A force platform is a tool used to analyze the performance of athletes by measuring the vertical force the athlete exerts on the ground as a function of time. Starting from rest, a 65.0-kg athlete jumps down onto the platform from a height of 0.600 m. While she is in contact with the platform during the time interval 0< t < 0.800 s, the force she exerts on it is described by the function F = 9 200t – 11 500 t 2 where F is in newtons and t is in seconds. (a) What impulse did the athlete receive from the platform? (b) With what speed did she reach the platform? (c) With what speed did she leave it? (d) To what height did she jump upon leaving the platform?
Solution Summary: The author explains that the impulse received from the platform to the athlete is 981.33Ncdot s.
Review. A force platform is a tool used to analyze the performance of athletes by measuring the vertical force the athlete exerts on the ground as a function of time. Starting from rest, a 65.0-kg athlete jumps down onto the platform from a height of 0.600 m. While she is in contact with the platform during the time interval 0<t< 0.800 s, the force she exerts on it is described by the function
F = 9 200t – 11 500 t2
where F is in newtons and t is in seconds. (a) What impulse did the athlete receive from the platform? (b) With what speed did she reach the platform? (c) With what speed did she leave it? (d) To what height did she jump upon leaving the platform?
The Zacchini family was renowned for their human- cannonball act in which a family member was shot from a cannon using either elastic bands or compressed air. In one version of the act, Emanuel Zacchini was shot over three Ferris wheels to land in a net at the same height as the open end of the cannon and at a range of 69 m. He was propelled inside the barrel for 5.2 m and launched at an angle of 53. If his mass was 85 kg and he underwent constant acceleration inside the barrel, what was the magnitude of the force propelling him? (Hint: Treat the launch as though it were along a ramp at 53. Neglect air drag.)
A man ( mass = 100 kg) fall freely from rest and strikes the ground. During the collision with the ground, he comes to rest in a time of .2s. The average force exerted on her by the ground is + 2000 N, where the upward direction is taken to be the positive direction.
A) from what height did he just fall? Assume the only force acting on him during the collision is that of the ground.
B) suppose instead of the man, a 5 kg rubber ball was dropped from the same vertical distance and the ball bounced back conserving the linear momentum. What would be the velocity of the ball just when it bounced back?
A projectile of mass 0.719 kg is shot straight up with an initial speed of 22.1 m/s. (a) How high would it go if there were no air resistance? (b) If the projectile rises to a maximum height of only 8.70 m, determine the magnitude of the average force due to air resistance.
Chapter 9 Solutions
Physics for Scientists and Engineers, Technology Update (No access codes included)
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.