Work done by gravity is the negative of the change in gravitational potential energy

Steps:

• Compute the car's weight: mg = 500 kg × 10 N/kg = 5000 N downward.
• Work by gravity opposes upward motion: W_grav = - (mg × h), where h is vertical height from diagram.
• Diagram implies h = 1 m, so |W_grav| = 5000 N × 1 m = 5000 J.
• Constant speed means net force zero, but gravity's work remains -mgh.

Why B is correct:

• Matches mgh = 500 × 10 × 1 = 5.0 × 10³ J, the magnitude of gravity's work per energy conservation.

Why the others are wrong:

• A assumes h = 10 m, exceeding diagram height.
• C assumes h = 2 m, double the actual rise.
• D assumes h = 0.2 m, underestimating the hill.

Final answer: B