In which of these situations is the most work done against gravity?
(Take the acceleration due to gravity g=9.8 m s−2g = 9.8\text{ m s}^{-2}g=9.8 m s−2)
A 15 kg15\text{ kg}15 kg crate is pulled 8 m8\text{ m}8 m up a ramp inclined at 30∘30^\circ30∘ to the horizontal
A 25 kg25\text{ kg}25 kg crate is pulled 6 m6\text{ m}6 m up a ramp inclined at 45∘45^\circ45∘ to the horizontal
A 40 kg40\text{ kg}40 kg crate is pulled 5 m5\text{ m}5 m up a ramp inclined at 60∘60^\circ60∘ to the horizontal
A 80 kg80\text{ kg}80 kg crate is pulled 4 m4\text{ m}4 m up a ramp inclined at 30∘30^\circ30∘ to the horizontal