Explanation:
Given that,
The initial velocity of a skater is, u = 5 m/s
She slows to a velocity of 2 m/s over a distance of 20 m.
We can find the acceleration of skater. It is equal to the rate of change of velocity. So, it can be calculated using third equation of motion as follows :

a = acceleration

So, her acceleration is
and she is deaccelerating. Also, her initial velocity is given i.e. 5 m/s.
Answer:
<h2>E. 3.95kW</h2>
Explanation:
Power is defined as the rate of workdone.
Power = Workdone/time taken
Given Workdone = Force * distance
Power = Force * distance/time taken
Power = mgd/t (F = mg)
m = mass of the sand in kg
g = acceleration due to gravity in m/s²
d = vertical distance covered in metres
t = time taken in seconds
Given m = 2000kg, d = 12m, t = 1min = 60secs, g = 9.8m/s²
Power = 2000*9.8*12/60
Power = 3920Watts
Minimum rate of power that must be supplied to this machine is 3920Watts or 3.92kW
Answer:

Explanation:
This is a uniformly accelerated motion, so we can determine the deceleration of the car by using a suvat equation:

where
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance covered
For the car in this problem,
u = 27.8 m/s
v = 0
s = 17 m
Solving for a, we find the acceleration:

Yes there is.
Momentum of an object is (its mass) times (its speed) .
Absolute, Atmospheric, Differential, and Gauge Pressure