By counting the number of crests that pass in a given amount of time, a person can calculate the
1 answer:
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Answer:
W = 1.432 KJ
Explanation:
given,
mass = 22.2 Kg
angle of the rope = 27.5°
distance on the ground = 24 m
kinetic friction= μ = 0.32
acceleration due to gravity, g = 9.8 m/s²
Work done = ?
W = F d cosθ
a = 0 because it is moving with constant speed
equating all the forces acting in x direction
F cosθ = F friction = μN
equating all the forces acting in y direction
F sinθ + N -mg =0
now,
N = mg - F sinθ
putting value of N
F cosθ = μ mg -μ F sinθ
F (cosθ + μsinθ ) = μ mg
F =67.28 N
now,
W=F d cosθ
W =67.28 x 24 x cos(27.5)
W =1432.27 J
W = 1.432 KJ
To solve this problem we will use the concepts related to power, defined as the amount of energy applied over a period of time.
The energy in this case is the accumulated in the form of potential energy, over a period of time. Thus we will have that the mathematical expression of the power can be expressed as
Here,
E = Energy
t = time
As the energy is equal to the potential Energy we have tat
The weight (mg) of the man is 700N, the height (h) is 8m and the time is 10s, then:
Therefore the correct answer is A.