Mary spins a ball in a horizontal circle on a massless string. karen has a similar ball but
wants to spin hers faster. what could karen do to make it easier to start spinning the
mass from rest?
a. spin the ball on the moon
b. use a lighter ball
c. use a heavier ball
d. make a string longer

Avalue that describes how heavy an object is and is related to the force of gravity is

Gasoline comes from petroleum, which is made from ancient living things. petroleum, therefore, contains a type of energy. a. heat b. nuclear c. biological d. chemical potential

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s