4. A 5.0 g marble is fired vertically upward using a spring gun. The spring must be compressed 8 cm if the marble is to reach a target 20 m above the marble’s position on the compressed spring. (a) What is the change ∆Ug in the gravitational potential energy of the marble-Earth system during the 20 m ascent? (b) What is the change ∆Us in the elastic potential energy of the spring during it’s launch of the marble? (c) What is the spring constant of the spring?

If an object with an initial temperature of 300 k increases its temperature by 1°c every minute, by how many degrees fahrenheit will its temperature have increased in 10 minutes? (a) 6°f (b) 10°f (c) 18°f (d) 30°f

Which statement is true? a) the work done to lift an object 6 meters is greater than the gravitational potential energy it gains. b) the work required to push an object is less than the work required to pull an object the same distance. c) the work required to raise an object to a height is equal to the gravitational potential energy the object gains. d) the work done against gravity to lift an object straight up is greater than the work required to roll it up a ramp.

Which form of pure carbon is so hard that it can be used in cutting tools?