A man exerts a constant force to pull a 51-kg box across a floor at constant speed. He exerts this force by attaching a rope to
the box and pulling so that the rope makes a constant angle of 36.9∘ above the horizontal. The coefficient of kinetic friction for the box-floor interface is μk = 0.12. What is the work done by the man if he moves the box 10m
1 answer:
Answer:
W=561.41 J
Explanation:
Given that
m = 51 kg
μk = 0.12
θ = 36.9∘
Lets F is the force applied by man
Given that block is moving at constant speed it mans that acceleration is zero.
Horizontal force = F cos θ
Vertical force = F sinθ
Friction force Fr= μk N
N + F sinθ = m g
N = m g - F sinθ
Fr = μk (m g - F sinθ)
For equilibrium
F cos θ = μk (m g - F sinθ)
F ( cos θ +μk sinθ) = μk (m g
Now by putting the values
F ( cos 36.9∘ + 0.12 x sin36.9∘)=0.12 x 51 x 10
F= 70.2 N
We know that Work
W= F cos θ .d
W= 70.2 x cos 36.9∘ x 10
W=561.41 J
You might be interested in
Mario's velocity vector relative to the ice is
(note that all velocities mentioned here are given in m/s)
The puck is moving in a direction of 17.8 degrees west of south, or 252.2 degrees counterclockwise relative to east. Its velocity vector relative to the ice is then
The velocity of the puch relative to Mario is
Then, relative to Mario,
a. the puck is traveling at a speed of , and
b. is moving in a direction such that
which is about west of south.
Answer:
(a). The blood travel during this acceleration is 0.0231 m.
(b). The time for the blood to reach its peak speed is 0.0459 sec.
Explanation:
Given that,
Acceleration = 22.0 m/s²
Speed = 1.01 m/s
(a). We need to calculate the distance
Using equation of motion
Where, v = final speed
u = initial speed
a = acceleration
s = distance
Put the value into the formula
(b). We need to calculate the time
Using equation of motion
Put the value into the formula
Hence, (a). The blood travel during this acceleration is 0.0231 m.
(b). The time for the blood to reach its peak speed is 0.0459 sec.