Answer:
a) 4.40 s
b) 2.20 s
Explanation:
Given parameters are:
At constant power ,
initial speed of the car, 
final speed of the car,
mph
At full power,
initial speed of the car, 
final speed of the car,
mph
a)
At constant power, 
At full power, 
So 
So, time to reach 64 mph speed is 4 times more than the initial time
s
b)

For final 64 mph speed,
=
s
But the fact is that an accelerating object is an object that is changing it’s velocity.. for this reason , it can be safely concluded that an object moving in a circle at constant speed is indeed accelerating. It is accelerating because the direction of the velocity vector is changing .
Answer:
The average force exerted by the water on the ground is 17.53 N.
Explanation:
Given;
mass flow rate of the water, m' = 135 kg/min
height of fall of the water, h = 3.1 m
the time taken for the water to fall to the ground;

mass of the water;

the average force exerted by the water on the ground;
F = mg
F = 1.789 x 9.8
F = 17.53 N
Therefore, the average force exerted by the water on the ground is 17.53 N.
The answer to this question is microbiology