A 37000 kg space probe is travelling at a speed of 9100 m/s through deep space. Retrorockets are fired along?

Question

the line of motion to reduce the probe's speed. The retrorockets generate a force of 170000 N over a distance of 3400 km. What is the final speed of the probe?

Answer 1

Start with F = ma, so a = F/m = 170000/37000 = 170/37 m/s/s
(constant deceleration).

Then, v^2 - vo^2 = 2a(x - xo)

where vo = 9100 m/s; x - xo = 3,400,000 m

So v^2 = 9100^2 - 2 (170/37) (3,400,000)

= 100^2 [91^2 - (340/37)(340)]

= 100^2 [91^2 - (340^2)/37] = 51566757

v = 7181 m/s

Answer 2

Force times distance equals work, which equals change in kinetic energy