Question

A car starts out from rest (zero velocity) at an elevation of 500 m and drives up a hill to reach a final elevation of 2000m and a final velocity of 20 m/s. At the same time the entire car heats up so the Internal Energy of the car increases by 100 kJ. What is the total energy change of the car if its mass is 2000 kg?

Answer 1

Answer:29,930 kJ

Explanation:

Given

Car starts with an initial elevation of 500 m and drives up a hill to reach a final elevation of 2000 m

Final velocity (V)=20 m/s

Energy of car increases by 100 kJ

mass of car(m)=2000 kg

$Total Energy =\Delta PE+\Delta KE+\Delta U$

$\Delta PE=mg(\Delta h)=2000\times 9.81\times (2000-500)$

$\Delta PE=29,430 kJ$

$\Delta KE=m\frac{v_2^2-v_1^2}{2}$

$\Delta KE=2000\times \frac{20^2-0^2}{2}$

$\Delta KE=400 kJ$

$\Delta U=100 kJ$

Total Energy=29,430+400+100=29,930 kJ