8. First, Manuel throws a football with a force of 10 Newtons. Later, Manuel uses less force and throws the football with a force of 5 Newtons. Which statement is true? A The amount of force used decreases so the acceleration rate will decrease. B. The amount of force used decreases so the acceleration rate will increase. C. The amount of force used decreases but the acceleration rate remains the same, D. The amount of force used decreases but the acceleration rate is not affected

When you jump from an elevated position you usually bend your knees upon reaching the ground. by doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. in this way the average force your body experiences is a) less than 1/10 as great. b) more than 1/10 as great. c) about 1/10 as great.d) about 10 times as great.

Which is an example of an exothermic process?

Uranium has two naturally occurring isotopes. 238u has a natural abundance of 99.3% and 235u has an abundance of 0.7%. it is the rarer 235u that is needed for nuclear reactors. the isotopes are separated by forming uranium hexafluoride uf6, which is a gas, then allowing it to diffuse through a series of porous membranes. 235uf6 has a slightly larger rms speed than 238uf6 and diffuses slightly faster. many repetitions of this procedure gradually separate the two isotopes. what is the ratio of the rms speed of 235uf6 to that of 238uf6? express your answer to five significant figures.