Answer:
a. The one with the lesser mass.
Explanation:
Since , both are made of the same material , they will have same specific heat . On physical contact , heat will be exchanged between them with heat flowing from body at higher temperature to one at lower temperature . Amount of heat lost by one will be equal to amount of heat gained .
So temperature change will take place in both of them but they will not be same . Body of higher mass will undergo lesser change in temperature because of the following relation
Q = mcΔT
ΔT = Q / mc
ΔT ∝ 1 / m
change in temperature will be inversely proportional to mass of object if Q or heat exchanged is constant .
Answer:
Car has more power output than crane
Explanation:
We have given that mass of the crane m = 1000 kg
Height through which crane lift the steel beam h = 10 m
Acceleration due to gravity
So work done by crane
Time period is given as t = 5 sec
We know that power
Now mass of the car = 1000 kg
Initial velocity u = 0 m /sec
Final velocity v = 10 m/sec
We know that work done is equal to the change in kinetic energy
So work done
Time ids given as t = 2 sec
So power
So car has more power output than crane
Answer:
The efficiency is just 0.016
Explanation:
The efficiency is given by the useful energy ÷ by the total energy.
1 W is the same that 1 joule per second
If you do the math:
1.6/100=0.016
Answer:
No
Explanation:
Unless there are other external forces, this will never be true. Because according to energy conservation, potential energy will be converted to kinetic energy as the ball falls down (so it loses height and gain speed). And vice versa, kinetic to potential when it bounces back. So the potential energy after must be the same (or smaller if losing heat to external environment), so it can only get the the same height or less, but not more.