216 joules of energy is required to raise the temperature of aluminium from 15 degrees celsius to 35 degrees celsius. calculate the mass of aluminium.
note : the specific heat capacity of aluminium is 9.2 x 10^2

Will you chech and finish these for me, because i am stumped with them.

Under the action of a constant force an object accelerates at 7.8 m/s2. what will the acceleration be if (a) the force is halved? (b) the object's mass is halved? (c) the force and the object's mass are both halved? (d) the force is halved and the object's mass is doubled?

If two students are running down the hall toward each other, trying to get to class, and they have the same mass and acceleration, what will happen when they collide? will their forces cancel out or will each one experience a reaction?