C. is the answer because acceleration is the change in velocity in time while velocity is speed with a direction
Weight is based on density mass is not.
Answer:
116 N.
Explanation:
Given,
mass of the ball, m = 0.145 Kg
initial speed = 0 m/s
Final speed = 40 m/s
time = 50 ms = 0.05 s
Force is equal to change in momentum per unit time
F = 116 N
Force of the pitcher hand on the ball is equal to 116 N.
Answer:
1) True: Spring A is stiffer than B (kA > kB). Less work must be expended on spring A if both springs are stretched by the same amount.
2) False: The kinetic energy of an object depends on the direction of the motion involved.
3) True: The work done to raise a box onto a platform does not depend on how fast it is raised.
4) True: The friction force is a non-conservative force.
5) True: The kinetic energy can be negative.
6) False: The kinetic energy does not depend on the reference frame of the observer.
7) False: Work can be done in the absence of motion.
8) False: If the moon revolves around the earth in a perfectly circular orbit, then the earth does do work on the moon.
Answer:
when the old wooden stiff poles were being used, none of the kinetic energy during the run-up was stored in the pole. With the new fiber glass flexible pole, some of that energy is stored in the flexing of the pole and then released as the pole straightens out at the top of its arc. Where 13 ft was considered an excellent competition vault with the stiff pole, the additional boost from the stored energy in the flex pole has made 17 ft vaults the winning heights.
Explanation:
when the old wooden stiff poles were being used, none of the kinetic energy during the run-up was stored in the pole. With the new fiber glass flexible pole, some of that energy is stored in the flexing of the pole and then released as the pole straightens out at the top of its arc. Where 13 ft was considered an excellent competition vault with the stiff pole, the additional boost from the stored energy in the flex pole has made 17 ft vaults the winning heights.
The flexible fiberglass poles can bend more than wooden ones, before breaking. This meant that fiberglass poles are able to store more energy than wooden ones, and provide an additional increase in height to the vaulter, when the pole straightens out near the top of the vault.
