Question

girl riding a bicycle along a straight road with a speed of 5 metre per second throws a stone of mass 0.5 kg which has a speed of 15 metre per second with respect to ground along the direction of motion the mass of the girl and the bicycle is 50 kg does the speed of the bicycle change after the stone is thrown what is the change in speed so​

Answer 1

♦ Mass of girl & bicycle = 50 kg

♦ Mass of stone = 0.5 kg

♦ Velocity of girl along with bicycle = 5 m/s

♦ Velocity of stone after being thrown = 15 m/s

Now,

$v = \frac{m_{1}u_{1} + m_{2}u_{2}}{m_{1} + m_{2}} \\ \\ \: \: \: = \frac{(50 \times 5) + (\frac{5}{10} \times 15) }{50 + 0.5} \\ \\ \: \: \: = \frac{1250 + 7.5}{50.5} \\ \\ \: \: \: = \frac{1257.5}{50.5} = \frac{12575}{505} = 24.9 \\ \\ \: \: \: = { \boxed{ \red{25 {ms}^{ - 1} }}}$