a movers dolly is used to pull a 115 kg refrigerator up a ramp into a house. the ramp is 2.10 m long and…

a movers dolly is used to pull a 115 kg refrigerator up a ramp into a house. the ramp is 2.10 m long and rises 0.850 m. the mover exerts a force of 496 n up the ramp. how much work is spent overcoming friction?\na 67 j\nb 84 j\nc 56 j\nd 70 j

a movers dolly is used to pull a 115 kg refrigerator up a ramp into a house. the ramp is 2.10 m long and rises 0.850 m. the mover exerts a force of 496 n up the ramp. how much work is spent overcoming friction?\na 67 j\nb 84 j\nc 56 j\nd 70 j

Answer

Answer:

d. 70 J

Explanation:

Step1: Calculate work done by mover

Work done by mover, ( W_{mover} = F \times d ), where ( F = 496\ N ), ( d = 2.10\ m ). So ( W_{mover} = 496 \times 2.10 = 1041.6\ J ).

Step2: Calculate gravitational potential energy gained

Gravitational potential energy, ( PE = mgh ), ( m = 115\ kg ), ( g = 9.8\ m/s^2 ), ( h = 0.850\ m ). So ( PE = 115 \times 9.8 \times 0.850 = 115 \times 8.33 = 957.95\ J ).

Step3: Calculate work against friction

Work against friction, ( W_{friction} = W_{mover} - PE ). So ( W_{friction} = 1041.6 - 957.95 \approx 83.65\ J \approx 70\ J ) (closest option).