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## Homework Statement

A spaceship of mass [tex]2000000kg[/tex] is moving with a constant velocity of [tex]3.0 \times 10^4 ms^{-1}[/tex]. It is suddenly hit by a mysterious force of [tex]8.0 \times 10^{10}N[/tex] for [tex]10s[/tex] in the opposite direction to its motion. What is the final velocity and direction of motion?

## Homework Equations

[tex]Force = \frac{Change \ in \ momentum}{Time}[/tex]

## The Attempt at a Solution

[tex]m = 2000000kg \ , \ u = 3.0 \times 10^4 ms^{-1} \ , \ F = 8.0 \times 10^8 \ , \ t = 10s[/tex]

[tex]Change \ in \ momentum = Force \times Time[/tex]

[tex]mv - mu = F \times t[/tex]

[tex]2000000 \times v - 2000000 \times 3.0 \times 10^4 = 8.0 \times 10^8 \times 10[/tex]

[tex]2000000v = 8.0 \times 10^8 \times 10 + 2000000 \times 3.0 \times 10^4[/tex]

[tex]v = \frac{8.0 \times 10^8 \times 10 + 2000000 \times 3.0 \times 10^4}{

2000000}[/tex]

[tex]v = 3.4 \times 10^4 ms^{-1}[/tex]

and the direction of motion is in the opposite direction because momentum after collision is greater then momentum before collision.

Are my answers correct?