Which of the following statements is true? If a hypothesis is proven false, a mistake has been made in the experiment.

The independent variable is what changes as a result of the dependent variable.

Changes in the independent variable cause changes in the dependent variable.

Once a hypothesis is proven true, it becomes a theory and cannot be disproved.

Can you match these to the correct definition

In a game of pool, ball a is moving with a velocity v0 of magnitude v0 = 15 ft/s when it strikes balls b and c, which are at rest and aligned as shown. knowing that after the collision the three balls move in the directions indicated and assuming frictionless surfaces and perfectly elastic impact (that is, conservation of energy), determine the magnitudes of the velocities va, vb, and vc.

Vi. on another planet, a spring with constant 4.7 n/m is set up and allowed to expand verticaly freely. 8.4kg mass is placed on the spring and the spring extends 5.28m. calculate the exected extension on earth.