When calculating power what two pieces of information are needed?

a. watts and time
b. distance and mass
c. work and mass
d. work and time

When a light bulb shines, it gives off light energy and energy. a. heat b. potential c. chemical d. electrical

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

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?