Answer:
Explanation:
(ΔK + ΔUg + ΔUs + ΔEch + ΔEth = W)
ΔK is increase in kinetic energy . As the athelete is lifting the barbell at constant speed change in kinetic energy is zero .
ΔK = 0
ΔUg is change in potential energy . It will be positive as weight is being lifted so its potential energy is increasing .
ΔUg = positive
ΔUs is change in the potential energy of sportsperson . It is zero since there is no change in the height of athlete .
ΔUs = 0
ΔEth is change in the energy of earth . Here earth is doing negative work . It is so because it is exerting force downwards and displacement is upwards . Hence it is doing negative work . Hence
ΔEth = negative .
b )
work done by athlete
= 400 x 2 = 800 J
energy output = 800 J
c )
It is 25% of metabolic energy output of his body
so metalic energy output of body
= 4x 800 J .
3200 J
power = energy output / time
= 3200 / 1.6
= 2000 W .
d )
1 ) Since he is doing same amount of work , his metabolic energy output is same as that in earlier case .
2 ) Since he is doing the same exercise in less time so his power is increased . Hence in the second day his power is more .
Answer:
Liquid
Explanation:
Substance that assumes shape of the container, slides past each other, has no definite shape but definite volume, not easily compressible, and flows easily.
The assumption that the cosmic microwave background
is the remnant of the environment at the time of the big bang
or very shortly after it explains very well what we observe now.
So it is the current prevailing theory. "Believe" is not involved.
Answer:2.17 rad/s
Explanation:
Given
Each wheel has moment of inertia 
Linear speed speed 
angular speed of tire 
moment of inertia of motorcycle 
Initial moment of inertia 
Due to absence of external Torque we can Conserve Angular Moment of inertia
