Answer:1/4 the brightness of star b
Explanation:
Velocity is defined by rate of change in the position
which we can also write as

while acceleration is defined as rate of change in velocity

so acceleration and velocity both are rate of change in position and rate of change in velocity with respect to time respectively
out of all above statement the correct answer must be
<u>Acceleration equals change in velocity divided by time. </u>
Well, you gave us the formula to calculate power from work and time,
but you didn't give us the formula for work. We have to know that.
Work = (force) x (distance)
The work to raise Sara to the top of the hill is
Work = (300 N) x (15 meters)
= 4,500 newton-meters = 4,500 joules .
Now we're ready to use the formula that you gave us. (Thank you.)
Power = (work) / (time)
= (4,500 joules) / (10 seconds)
450 joules/second = 450 watts.
Vector quantities have both magnitude and direction. Distance is a scalar quantity. It refers only to how far an object has traveled. For example, 4 feet is a distance; it gives no information about direction.
Answer:
The coefficient of performance for the cycle is 2.33.
Explanation:
Given that,
Output energy 
Work done 
We need to calculate the coefficient of performance
Using formula of the coefficient of performance

We need to calculate the 

Put the value into the formula



Now put the value of
into the formula of COP


Hence, The coefficient of performance for the cycle is 2.33.