Answer:
Explanation:
Given that
The mass of the body is 0.04kg
M=0.04kg
The radius of the paths is 0.6m
r=0.6m
The normal force exerted at A is 3.9N
Fa=3.9N
The normal force exerted at B is 0.69N
Fb=0.69N
Then work done by friction from point A to B will be the change in K.E
W=∆K.E+P.E
So we need to know the velocity at both point A and B
Then since the centripetal force is given as
Ft=mv²/r
Then,
For point A
Fa=mv²/r
3.9=0.04v²/0.6
3.9=0.0667v²
v²=3.9/0.0667
v²=58.5
v=√58.5
v=7.65m/s
Va=7.65m/s
Now at point B
Fb=mv²/r
0.69=0.04v²/0.6
0.69=0.0667v²
v²=0.69/0.0667
v²=10.35
v=√10.35
v=3.22m/s
Vb=3.22m/s
Then, the work done is
W=∆K.E+P.E
P.E is given as mgh
The height will be 2R =1.2m
P.E=mgh
P.E=0.04×9.81×1.2
P.E=0.471J
Final kinetic energy at B minus initial kinetic energy at A
W=K.Eb-K.Ea
K.E is given as 1/2mv²
W=1/2m(Vb²-Va²) +P.E
W=0.5×0.04(3.22²-7.65²) +0.471
W=0.5×0.04×(-48.1541) +0.471
W=-0.96+0.471
W=-0.49J
work was done on the block by friction during the motion of the block from point A to point B is 0.49J.
Friction opposes motions and that is why the work done is negative
Answer:
I'm pretty Sure. Yea look.
Explanation:
Up to 60% of the human adult body is water. According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%.
Answer:
110.7 J
Explanation:
Hooke's law is represented by the formula:
F = ke where F is the force in Newton, K is force constant and e is extension in m
work done = 1/2ke² = 1/2 K ( e² - e₀²) and e₀ is the extension at relaxed length
e₀ =0
work done = 0.5 × 82N/m × (2.70 m)² = 110.7 J
Answer:
A = 2.1 × 10^(-4) m²
Explanation:
We are given;
Temperature; T = 2450 K
Emissivity; ε = 0.35
Bulb rating; H = 150 W
To calculate the surface area, we will use the formula;
H = AεσT⁴
Where σ is stephan boltzman constant with a value of 5.66 × 10^(−8) W/m²⋅K⁴
Making A the subject of the formula, we have;
A = H/εσT⁴
Plugging in the relevant values gives;
A = 150/(0.35 × 5.66 × 10^(−8) × 2450⁴)
A = 2.1 × 10^(-4) m²