Question

A 960 kg motorboat accelerates away from a dock at 2.3 m/s2 .t Its propeller provides a thrust force of 4.1 kN .

Answer 1

m = 960 kg a = 2.3 m/s^2 F = ma = 960 x 2.3 = 2208 N Thrust force = Fa + Fd Drag Force Fd = 4100 - 2208 = 1892 N

Answer 2

For a motorboat:
F m = m · a = 960 kg · 2.1 m/s² = 2208 N
Propeller provides trust force F p = 4.1 kN = 4100 N
We have to find drag force exerted by the water on the boat.
F = 4100 N - 2208 N = 1892 N = 1.9 kN ( with 2 significant figures )
Answer: 1.9 kN