Answer:
Explanation:
Given that,
A crate of mass M = 50kg
The crate is pulled along an horizontal floor by a string at an angle
Force pulling the crate
F = 210N
Angle θ = 20° to the horizontal
Distance moved by crate d=3m
A. Work done by force
W = FdCosθ
W = 210 × 3 × Cos20
W = 592J
B. Work done by Gravitational force?
Work is define as the dot product of force and displacement in the direction of the force.
Since the gravitational force does not cause the crate to move any distance downward
Then,
W(gravity) = mg×d
distance d=0
W(gravity) = 0 J
C. Work done by normal?
Since, the normal force did not cause the crate to move upward by any distance
Then,
W(normal) = 0J
D. The total workdone?
The only workdone on the crate is by the person
Then, the total workdone is the workdone by the person
W = 592 J
The work done on the crate by the worker's force is 592 J.
Given that,
Mass of the crate, m = 50kg
Force applied by the worker, F = 210N
Angle to the horizontal, θ = 20°,
Distance moved by crate, d=3m
A force causes an object with mass to change its velocity, therefore, the acceleration. acceleration caused by a force is always in the direction of force applied.
Also, we know that work done is always given as the product of force and displacement in the direction of the force.
[tex]\bold{Work= Force\times displacement}[/tex]
(a.) work done on the crate by the worker's force,
As the force is been applied at an angle directed 20° above the horizontal.
Therefore, the force is causing the crate to move in the horizontal direction, thus, only the horizontal component of the force is taken.
[tex]\begin{aligned}W &= F\ Cos\theta \times d\\&=210 \times Cos (20^o)\times 3\\&= 592.00\ J\\\end{aligned}[/tex]
(b) work done on the crate by the gravitational force,
[tex]\bold{Gravitational\ force = Mass\times acceleration\ due\ to\ gravity}[/tex]
As the gravitational force is always applied perpendicular to the horizontal.
Therefore, the gravitational force is not causing the crate to displace anywhere, thus, the displacement is zero.
[tex]\begin{aligned}W &= gravitational\ force \times displacement\\&=m\times g \times d\\&=50\times 9.81\times 0\\&= 0\ J\\\end{aligned}[/tex]
Hence, work done on the crate by the gravitational force is 0 J.
(c.) work done on the crate by the normal,
Normal is the contact force that is perpendicular to the surface with which the object has contact.
As the normal force did not cause the crate to displace upward by any distance.
(d.) The total work done on the crate,
As discussed above the only work done on the crate is by the worker.
Therefore, The total work done on the crate is 592 J.
To know more visit:
https://brainly.com/question/3902440
