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

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:  

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 =?

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

I hope it helps you!                                                                   

gravity

explanation:

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)