Answer:
20m
6.9s
Explanation:
The vertical velocity of the ball is 20m/s. We can calculate the kinetic energy which gets transferred to potential energy once it gets to the top.
we can subtitute v = 20m/s and g = 10m/s2
So the ball could go 20m high from the child hand, or 120m fro the bottom of the cliff.
The time it takes for the ball to travels to the top is the time it takes for it to decelerate from 20m/s to 0m/s with gravitational deceleration g = 10m/s2
t = v / g = 20 / 10 = 2s
Then the ball will start accelerating down ward with a constant acceleration of g = 10m/s. In order to cover distance d of 120m from the top to the bottom of the cliff
So the total time it takes is 4.9 + 2 = 6.9s
Answer:
A. The potential energy of the positively charge proton from 5v to 7.5v will increase because in an electric field work is done on the proton to move it to a point of higher potential
B. when an electron is moved from 7.5v to 5v it loses potential energy due to the charges lost so as to bring it to a point of lower potential
Explanation:
Answer:
The inventors claim is not real
a) No the the freezer cannot operate in such conditions
Explanation:
From the question we are told that
The power input is 
The rate of heat transfer 
The temperature of the freezer content is 
The ambient temperature is 
Generally the coefficient of performance of a refrigerator at idea conditions is mathematically represented as
substituting values
Generally the coefficient of performance of a refrigerator at real conditions is mathematically represented as
substituting values
Now given that the COP of an ideal refrigerator is less that that of a real refrigerator then the claims of the inventor is rejected
This is because the there are loss in the real refrigerator cycle that are suppose to reduce the COP compared to an ideal refrigerator cycle where there no loss that will reduce the COP
