A 3.8kw elective motor powers an inclined conveyer belt. It is designed to lift heavy boxes from the warehouse floor to loading
1 answer:
Answer:
See the answers below
Explanation:
To solve this problem we must use the definition of power and work in physics.
a)
The function of the conveyor belt is to carry the boxes from an initial point that is at low altitude to an end point that is at high altitude. In this way the conveyor belt prints a speed to the box to be able to raise it to the required vertical distance.
Since we have a velocity at the beginning and then we place the box at a high position, where then the box remains at rest, we can say that it converts kinetic energy to potential energy.
b)
Power is defined as the relationship of work over time. Therefore we have:
where:
P = power = 3.8 [kW] = 3800 [W]
W = work [J]
t = time = 14 [s]
c)
Since the given time is equal to the given time at Point b, we can use the same work calculated.
We know that work is defined as the product of force by the distance traveled.
So, the force is equal to:
Now we know that force is defined as the product of mass by gravitation acceleration.
where:
F = force or weight = 10037.73 [N]
g = gravity acceleration = 9.81 [m/s²]
m = mass [kg]
d)
This part can be solved by means of the energy conservation theorem, where the potential energy is transformed into kinetic energy or vice versa.
where:
h = elevation = 4.7 [m]
v = velocity [m/s]
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Answer:
The angle of elevation of the rocket is increasing at a rate of 48.780º per second.
Explanation:
Geometrically speaking, the distance between the rocket and the observer (), measured in kilometers, can be represented by a right triangle:
(1)
Where:
- Horizontal distance between the rocket and the observer, measured in kilometers.
- Vertical distance between the rocket and the observer, measured in kilometers.
The angle of elevation of the rocket (), measured in sexagesimal degrees, is defined by the following trigonometric relation:
(2)
If we know that , then the expression is:
And the rate of change of this angle is determined by derivatives:
Where:
- Rate of change of the angle of elevation, measured in sexagesimal degrees.
- Vertical speed of the rocket, measured in kilometers per hour.
If we know that and
, then the rate of change of the angle of elevation is:
The angle of elevation of the rocket is increasing at a rate of 48.780º per second.
At 10 m/s, it will take
(2 m)/(10 m/s) = 0.2 s
to bridge the gap.
_____
However, it will take an additional 0.514 seconds (0.714 s total) for the policeman to land on the building below. The answer depends on the meaning of the question.
(2 m)/(10 m/s) = 0.2 s
to bridge the gap.
_____
However, it will take an additional 0.514 seconds (0.714 s total) for the policeman to land on the building below. The answer depends on the meaning of the question.