Question

The Jensens dccided to spend their family vaeation white water rafting. During one segment of their trip down the river, the raft (total mass = 544 kg) has an initial speed of 6.75 m/s. The raft then drops a vertical distance of 14.0 m, ending with a final speed of 15.2 m/s. How much work was done on the raft by nonconservative forces?

Answer 1

Answer:

24,187.04 J ≈ 24,200 J

Explanation:

mass (m) = 544 kg

initial speed (u) = 6.75 m/s

final speed (v) = 15.2 m/s

change in height (Δh) = -14 m (negative sign is because there is a decrease in height )

acceleration due to gravity (g) = 9.8 m/s^{2}

How much work was done on the raft by non conservative forces?

work done = change in energy of the system = change in kinetic energy + change in potential energy

work done = ($0.5m(v^{2} -u^{2} )$) + (mgΔh)

work done = ($0.5x544x(15.2^{2} -6.75^{2} )$) + (544 x 9.8 x (-14))

work done = 50449.76 - 74,636.8

work done = 24,187.04 J ≈ 24,200 J