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 .
Work = force in the direction of the movement x distance = 27 N x 1.7 m
Work = 45.9 joules
Answer: option c.
Answer:
A: receives information
B: Carries information away from the cell body
C: Delivers information to the next cell
Explanation:
The answer is to the question is c
2. False
Explanation: When a wave's energy increases, the wave length/frequency decreases.
3. Bass Guitar
Explanation: It has the lowest frequency.
4. Frequency
Explanation: The frequency is the number of vibrations per unit of time or the number of waves that passes a point per unit of time.
