Question

DESPERATEA rocket of mass 40 000 kg takes off and flies to a height of 2.5 km as its engines produce 500 000 N of thrust.
b The rocket engines switch off at 2.5 km and the rocket slows down as it moves up until it stops momentarily and then falls to the ground.
i Calculate the rocket’s energy when the rocket engines were switched off.
ii Calculate the speed of the rocket when the rocket engines were switched off.

Answer 1

Answer:

i=1250000000j

ii=

Explanation:

i . Energy= force × distance

= 500000N × 2500m

= 1250000000j

ii . Force = mass × acceleration

500000N= 40000kg × a

500000÷40000= 12.5m/s^2

S=1/2at^2

2500m=1/2×12.5×t^2

2500m=6.25 ×t^2

2500÷6.25=400

400= t^2

√400= √t^2

t = 20seconds

Speed= distance ÷ time

= 2500÷20

= 125m/s