An asteroid is moving along a straight line. a force acts along the displacement of the asteroid and slows it down. the asteroid has a mass of 4.3 × 104 kg, and the force causes its speed to change from 7600 to 5000 m/s. (a) what is the work done by the force? (b) if the asteroid slows down over a distance of 1.4 × 106 m determine the magnitude of the force.

i have part a, just need part b
a= -7.048e11 j

a)

b)

Explanation:

a)

= mass of the asteroid = 43000 kg

= initial speed of asteroid = 7600 m/s

= final speed of asteroid = 5000 m/s

= Work done by the force on asteroid

Using work-change in kinetic energy theorem

b)

= magnitude of force on asteroid

= distance traveled by asteroid while it slows down = 1.4 x 10⁶ m

Work done by the force on the asteroid to slow it down is given as

i would think form in reponse to tensional forces

f=ma newton

f=100x2.5=250n