Answer:
The energy that will go will for thermal store of the surroundings is 20 J.
Step-by-step 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.