Answer:
A
Explanation:
The equation of power is defined as Power = Workdone/Time Taken
And workdone = Force x Distance so using these equations we get they workdone is, 200x 10 = 2000Nm.
Dividing workdone with time will yield power, 2000 ÷ 8 = 250 Nm/s = 250W.
The strength of the friction doesn't matter. Neither does the distance or the time the asteroid takes to stop. All that matters is that the asteroid has
1/2 (mass) (speed squared)
of kinetic energy when it lands, and zero when it stops.
So
1/2 (mass) (original speed squared)
is the energy it loses to friction in order to come to rest.
The correct answer is a, lunar eclipse
Answer:
doubled the initial value
Explanation:
Let the area of plates be A and the separation between them is d.
Let V be the potential difference of the battery.
The energy stored in the capacitor is given by
U = Q^2/2C ...(1)
Now the battery is disconnected, it means the charge is constant.
the separation between the plates is doubled.
The capacitance of the parallel plate capacitor is inversely proportional to the distance between the plates.
C' = C/2
the new energy stored
U' = Q^2 / 2C'
U' = Q^2/C = 2 U
The energy stored in the capacitor is doubled the initial amount.
