Question

a model rocket of mass 0.5 kg is launched straight up. At an altitude of 140 m, when its speed is 90 m/s, it spontaneously blows apart into two equal pieces. One piece continues upward at a speed of 10 m/s. How fast is the other piece moving

Answer 1

Answer:

The other piece is moving at 170 m/s.

Explanation:

To find the speed of the second piece can be found by conservation of linear momentum:  

$p_{i} = p_{f}$

$m_{1}v_{1} = m_{2}v_{2} + m_{3}v_{3}$

Where:

m₁: is the rocket's mass = 0.5 kg      

m₂ = m₃: is the mass of the two equal pieces = 0.25 kg

v₁: is the rocket speed = 90 m/s

v₂: is the speed of the first piece = 10 m/s

v₃: is the speed of the second piece =?

             

$0.5*90 = 0.25(10 + v_{3})$

$v_{3} = \frac{45}{0.25} - 10 = 170 m/s$

Therefore, the other piece is moving at 170 m/s.

I hope it helps you!