Answer:
Explanation:
To develop this exercise we proceed to use the kinetic energy equations,
In the end we replace
Here
meaning the 4 wheels,
So replacing
So,
Wavelength = velocity/frequency
wavelength = v/f
v= 13km/s = change this to m/s = 13000m/s
f= 14Hz
wavelength = 13000m/s÷14Hz =928.7 m
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 .
M = 4kg
F =8N
a..?
F =m.a
8 = 4.a
a = 2m/s^2
Explanation: Formulas you need to use:
K=0.5mass(Velocity^2)
km/h / 3.6 ===>M/S
Step 1:
convert km/h to m/s
Put the values in the formula :
