Answer:
-80 N
Explanation:
First of all, let's calculate the deceleration of the ball, which is given by:
[tex]a=\frac{v-u}{t}[/tex]
where
v = 0 m/s is its final velocity
u = 10 m/s is its initial velocity
t = 0.5 s is the time taken
Substituting,
[tex]a=\frac{0-10 m/s}{0.5 s}=-20 m/s^2[/tex]
And now we can calculate the average net force required to stop the ball by using Newton's second law: in fact, the net force is equal to the product between the ball's mass (4 kg) and the acceleration, so:
[tex]F=ma=(4 kg)(-20 m/s^2)=-80 N[/tex]
Where the negative sign simply means that the force is in the opposite direction to the motion of the ball.
