A pole vaulter of mass 60.0 kg vaults to a height of 6.50 m before dropping to thick padding placed below to cushion her fall. If the padding brings her to a stop in a time of 0.480 s, what is the average force on her body due to the padding during that time. Interval? Enter a positive value if the average force is up and a negative value if the average force is down.

A pole vaulter of mass 60.0 kg vaults to a height of 6.50 m before dropping to thick padding placed below to cushion her fall. If the padding brings her to a stop in a time of 0.480 s, what is the average force on her body due to the padding during that time. Interval? Enter a positive value if the average force is up and a negative value if the average force is down.

University Physics Volume 1

18th Edition

ISBN:9781938168277

Author:William Moebs, Samuel J. Ling, Jeff Sanny

Publisher:William Moebs, Samuel J. Ling, Jeff Sanny

Chapter5: Newton's Law Of Motion

Section: Chapter Questions

Problem 43P: A rocket sled accelerates at a rate of 49.0m/s2 . Its passenger has a mass of 75.0 kg. (a) Calculate...

See similar textbooks

Similar questions

A motorcycle and rider have a total mass equal to 300 kg. The rider applies the brakes, causing the motorcycle to accelerate at a rate of 5 m/s2. What is the net force on the motorcycle?
A device used since the 1940s to measure the kick 01 recoil of the body due to heartbeats is the “ballistocardiograph,” What physics principle(s) are involved here to measure the force of cardiac contraction? How might we construct such a device?
An Atwoods machine (Fig. 4.38) consists of two masses: one of mass 3.00 kg and the other of mass 8.00 kg. When released from rest, what is the acceleration of the system?
What force does a trampoline have to apply to a 45.0-kg gymnast to accelerate her straight up at 7.50 m/s2? Note that the answer is independent of the velocity of the gymnast—she can be moving either up or down, or be stationary.
(a) Give an example of different net external forces acting on the same system to produce different accelerations. (b) Give an example of the same net external force acting on systems of different masses, producing different accelerations. (c) What law accurately describes both effects? State it in words and as an equation.
A body of mass m has initial velocity v0 in the positive x -direction. It is acted on by a constant force F for time t until the velocity becomes zero; the force continues to act on the body until its velocity becomes v0 in the same amount of time. Write an expression for the total distance the body travels in terms of the variables Indicated.
The wheels of a midsize car exert a force of 2100 N backward on the road to accelerate the car in the forward direction. If the force of friction including air resistance is 250 N and the acceleration of the car is 1.80 m/s2, what is the mass of the car plus its occupants? Explicitly show how you follow the steps in the Problem-Solving Strategy for Newton's laws of motion. For this situation, draw a free-body diagram and write the net force equation.
Suppose two children push horizontally, but in exactly opposite directions, on a third child in a wagon. The first child exerts a force of 75.0 N, the second a force of 90.0 N, friction is 12.0 N, and the mass of the third child plus wagon is 23.0 kg. (a) What is the system of interest if the acceleration of the child in the wagon is to be calculated? (b) Draw a free-body diagram, including all forces acting on the system. (c) Calculate the acceleration. (d) What would the acceleration be if friction were 15.0 N?
A person holds a ball in her hand, (a) Identify all the external forces acting on the ball and the Newton's third-law reaction force to each one. (b) If the ball is dropped, what force is exerted on it while it is falling? Identify the reaction force in this case. (Ignore air resistance.)
A block of mass 3m is placed on a frictionless horizontal surface, and a second block of mass m is placed on top of the first block. The surfaces of the blocks are rough. A constant force of magnitude F is applied to the first block as in Figure P4.68. (a) Construct free-body diagrams for each block. (b) Identify the horizontal force that causes the block of mass m to accelerate. (c) Assume that the upper block does not slip on the lower block, and find the acceleration of each block in terms of m and F. Figure P4.68
Astronauts in orbit are apparently weightless. This means that a clever method of measuring the mass of astronauts is needed to monitor their mass gains or losses, and adjust their diet. One way to do this is to exert a known force on an astronaut and measure the acceleration produced. Suppose a net external force of 50.0 N is exerted, and an astronaut’s acceleration is measured to be 0.893m/s2 . (a) Calculate her mass. (b) By exerting a force on the astronaut, the vehicle in which she orbits experiences an equal and opposite force. Use this knowledge to find an equation for the acceleration of the system (astronaut and spaceship) that would be measured by a nearby observer. (c) Discuss how this would affect the measurement of the astronaut’s acceleration. Propose a method by which recoil of the vehicle is avoided.
When a 1.50-kg dress hangs midway from a taut clothesline stretched between two poles planted 7.50 m apart, the clothesline is seen to sag 0.0500 m. a. Draw a free-body diagram of the dress. b. What is the tension produced on the clothesline by the dress? Assume the clothesline is massless.