A hot brass plate is having its upper surface cooled by impinging jet of air at temperature of 15°c and convection heat transfer
1 answer:
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Answer:
a. 79.1 N
b. 344 J
c. 344 J
d. 0 J
e. 0 J
Explanation:
a. Since the crate has a constant velocity, its net force must be 0 according to Newton's 1st law. The push force by the worker must be equal to the friction force
on the crate, which is the product of friction coefficient μ and normal force N:
Let g = 9.81 m/s2
b. The work is done on the crate by this force is the product of its force and the distance traveled s = 4.35
c. The work is done on the crate by friction force is also the product of friction force and the distance traveled s = 4.35
This work is negative because the friction vector is in the opposite direction with the distance vector
d. As both the normal force and gravity are perpendicular to the distance vector, the work done by those forces is 0. In other words, these forces do not make any work.
e. The total work done on the crate would be sum of the work done by the pushing force and the work done by friction
Answer:
The change in potential energy is
Explanation:
From the question we are told that
The magnitude of the uniform electric field is
The distance traveled by the electron is
Generally the force on this electron is mathematically represented as
Where F is the force and q is the charge on the electron which is a constant value of
Thus
Generally the work energy theorem can be mathematically represented as
Where W is the workdone on the electron by the Electric field and is the change in kinetic energy
Also workdone on the electron can also be represented as
Where considering that the movement of the electron is along the x-axis
So
substituting values
Now From the law of energy conservation
Where is the change in potential energy
Thus