A mass of 1 kg is thrown up with a velocity of 100 m / s. After 5 seconds, it explodes into two parts. One part of mass 400 g comes down with a velocity 25 m / s. The velocity of other part is (Take g =10 ms -2 )

Question

A mass of 1 kg is thrown up with a velocity of 100 m / s. After 5 seconds, it explodes into two parts. One part of mass 400 g comes down with a velocity 25 m / s. The velocity of other part is (Take g =10 ms -2 ) (A) 40 m / s uparrow (B) 40 m / s downarrow (C) 100 m / s uparrow (D) 60 m / s uparrow

Tardigrade Admin · Accepted Answer

Velocity after 5 sec , v = u - gt =100-10 × 5=50 m / s By conservation of momentum 1 × 50=0.4 ×(-25)+0.6 × v prime 60=0.6 × v prime ⇒ v prime=100 m / s upwards

Q. A mass of $1 k g$ is thrown up with a velocity of $100 m / s$ . After $5$ seconds, it explodes into two parts. One part of mass $400 g$ comes down with a velocity $25 m / s$ . The velocity of other part is (Take $g = 10 m s^{- 2}$ )

$40 m / s ↑$

$40 m / s ↓$

$100 m / s ↑$

$60 m / s ↑$

Velocity after $5 sec, v = u - g t$
$= 100 - 10 \times 5 = 50 m / s$
By conservation of momentum
$1 \times 50 = 0.4 \times (- 25) + 0.6 \times v^{'}$ $60 = 0.6 \times v^{'}$
$\Rightarrow v^{'} = 100 m / s$ upwards

Q. A mass of 1kg is thrown up with a velocity of 100m/s. After 5 seconds, it explodes into two parts. One part of mass 400g comes down with a velocity 25m/s. The velocity of other part is (Take g=10ms−2 )

40m/s↑

40m/s↓

100m/s↑

60m/s↑