Answer:
11.9 minutes
Explanation:
The journey is 5000 meters long. The time it takes in seconds for the journey at this speed is 5000/7 =714 seconds.
714/60=time in minutes =11.9 minutes approximately.
(a) 
The work-energy theorem states that the work done on the cheetah is equal to its change in kinetic energy:

where
m = 51.0 kg is the mass of the cheetah
u = 0 is the initial speed of the cheetah (zero because it starts from rest)
u = 31.7 m/s is the final speed
Substituting, we find

(b) 6.1 cal
The conversion between calories and Joules is
1 cal = 4186 J
Here the energy the cheetah needs is

Therefore we can set up a simple proportion

to find the equivalent energy in calories:

Answer:
<h2>a.The ball's vertical acceleration is downwards.</h2><h2>e.The ball's horizontal acceleration is zero</h2>
Explanation:
We are given that Sarah throws a tennis ball as far as she can.
At the moment the ball reaches its maximum height.
We have to find the true statement if air resistance is neglect.
When air resistance is negligible then the force act on the ball is force due to gravity.
The ball throw vertically then the acceleration act on the ball is acceleration due to gravity.
The value of g=-9.8 m/square sec
It acts on the ball in downward direction .
Therefore, the ball's vertical acceleration is downwards.
The horizontal acceleration is zero because the ball reaches at maximum height then there is no force which act in horizontal direction on the ball.
Therefore, horizontal acceleration of the ball is zero.
Hence, option a and e are true.