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

The other piece is moving at 170 m/s.

Step-by-step 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) = (45)/(0.25) - 10 = 170 m/s`

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

I hope it helps you!