A plastic rod is charged up by rubbing a wool cloth, and brought to an initially neutral metallic sphere that is insulated from
1 answer:
You might be interested in
Answer:
The minimum work per unit heat transfer will be 0.15.
Explanation:
We know the for a heat pump the coefficient of performance () is given by
where, is the magnitude of heat transfer between cyclic device and high-temperature medium at temperature
and
is the required input and is given by
,
being magnitude of heat transfer between cyclic device and low-temperature
. Therefore, from above equation we can write,
Given, and
. So, the minimum work per unit heat transfer is given by
The re<span>sistance of the second wire is 16 R.
where R is the resistance of the first wire.
R = </span>ρ
where l = length of the wire
A = area of the wire
A =
where, r = 
Thus, on finding the ratio of resistance of the two wires, we get,
here, R1 = R
l1 = 8m
l2 = 2m
A1=π
A1=π
we get. R2 = 16R
where R is the resistance of the first wire.
R = </span>ρ
where l = length of the wire
A = area of the wire
A =
Thus, on finding the ratio of resistance of the two wires, we get,
here, R1 = R
l1 = 8m
l2 = 2m
A1=π
A1=π
we get. R2 = 16R
Answer: Third option
F = 250w
Explanation:
The impulse can be written as the product of force for the time interval in which it is applied.
You can also write impulse I as the change of the linear momentum of the ball
So:
We want to find the force applied to the ball. We know that
milliseconds = 0.03 seconds
The initial velocity is zero.
The final speed
So
We must express the result of the force in terms of the weight of the ball.
We divide the expression between the acceleration of gravity
The answer is the third option