Question

It's very urgent pls solve it

Answer 1

MV = m(boy) . v(boy) + m(trolley) . v(trolley) ;

M= net mass in the end i.e boy+ trolley , V= Final velocity of boy + trolley.

Going by this,

MV = 50 * 5 + 20 * 1.5

MV = 280

so, V= 280/M, But M = 50 + 20 =70kg

Hence V = 4m/s