A0.45 kg soccer ball changes its velocity by 20.0 m/s due to a force applied to it in 0.10 seconds. what force was necessary for this change in velocity?

A175 g lump of molten lead at its melting point (327 c) is placed into 55.0 g of water at 20.0 c. the specific heat of lead is 130.j/kg c and the hf of lead is 20,400 j/kg. when the lead and the water have reached equilibrium, what is the temperature of the mixture?

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2