A 20 kg ball sits motionless at the top of a 10 meter high hill.
What is the Potential Energy of this ball at the top of the
hill?

Aball bearing at 220.0 °c is dropped into a cup containing 250.0 g of water at 20.0 °c. the water and ball bearing come to a temperature of 30.0 °c. what is the heat capacity of the ball bearing in j/°c? (hint: how are the algebraic signs of q related for the ball bearing and the water? )

Determine the fraction of the magnitude of kinetic energy lost by a neutron (m1 = 1.01 u) when it collides head-on and elastically with a target particle at rest which is 21h (heavy hydrogen, m = 2.01 u).

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?