A 10 kg boy standing in a 40 kg boat floating on water is 20 m from the shore of the river. If he moves 8 metres on the boat…

Q: A 10 kg boy standing in a 40 kg boat floating on water is 20 m from the shore of the river. If he moves 8 metres on the boat towards the shore, then how far is he from the shore now ?

Sol: Mass of the body (m) = 10 kg Mass of the boat (M) = 40 kg

Distance travelled by boy (l) = 8 m

distance travelled by the boat in opposite direction

$\large = \frac{m l}{M + m}$

$\large = \frac{10 \times 8}{40 + 10}$

= 1.6 m

Distance of the body from the shore is (20 – 8) + (1.6) = 13.6m