A ball is thrown with 50J of kinetic energy, it hits a target which moves with 30J of kinetic energy, how much energy goes to the thermal store of the surroundings?

The energy that will go will for thermal store of the surroundings is 20 J.

Explanation:

Given;

kinetic of the thrown ball, K.E₁ = 50 J

kinetic energy used to move the target, K.E₂ = 30 J

The excess energy that will go will for thermal store of the surroundings;

ΔK.E = K.E₁ - K.E₂

ΔK.E = 50J - 30J

ΔK.E = 20 J

Therefore, the energy that will go will for thermal store of the surroundings is 20 J.

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2