Answer:
16 m
Explanation:
For an object in uniformly accelerated motion (=with constant acceleration), the distance covered by the body can be found by using the following suvat equation:

where
s is the distance covered
u is the initial velocity
t is the time
a is the acceleration
For the body in this problem,
u = 0 (it starts from rest)
is the acceleration
Substituting t = 4 s, we find the distance covered:

Answer:
84.6 J
Explanation:
The work done by the force is given by

where
W is the work done
F = 15 N is the force applied
d = 6.0 m is the displacement
is the angle between the force's direction and the displacement
Substituting the numbers into the equation, we find

Answer:
The initial speed of the ball was 26.2 m/s
Explanation:
When the football player is in the air at his maximum height the vertical component of velocity is zero, To obtain the horizontal velocity when the player catches the ball we need to apply the linear momentum conservation theorem:

we need to obtain the time taken to go down.

We have a horizontal displacement and the time taken to stop, so:

so:
