If a tennis ball has a velocity of 18 m/s and a momentum of 1.06 kg • m/s, what is the mass of the tennis ball in grams? Round the answer to two significant figures.

If the spring constant k of a pogo stick is 3500 n m and the weight of the person on the pogo stick is 700 n, how much is the spring in the botom of the pogo stick compressed?

Of is j/kg·k. if a 2.6 kg of isk to k,is ?

First answer marked as brainiest which is the correct equation describing the first law of thermodynamics? a) when the internal energy of a system changes, it equals the amount of heat added plus the work done. b) when work is done by the piston, it is equal to the heat added plus the change in internal energy of the system. c) when heat is added to the system, it is equal to the amount of work done by the piston plus the change in internal energy of the system.