Answer:
Power input, P = 2880 watts
Explanation:
It is given that,
Voltage of the motor, V = 240 V
Current required, I = 12 A
Weight lifted, W = 2000 lb
It is lifting at a speed of 25 ft/min. We need to find the power input to the motor. The product of current and voltage is called power input of the motor.
P = 2880 watts
So, the power input of the motor is 2880 watts. Hence, this is the required solution.
Answer:
The work done by the force is 820.745 joules.
Explanation:
Let suppose that changes in potential energy can be neglected. According to the Work-Energy Theorem, an external conservative force generates a change in the state of motion of the object, that is a change in kinetic energy. This phenomenon is describe by the following mathematical model:
Where:
- Work done by the external force, measured in joules.
,
- Translational potential energy, measured in joules.
The work done by the external force is now cleared within:
After using the definition of translational kinetic energy, the previous expression is now expanded as a function of mass and initial and final speeds of the object:
Where:
- Mass of the object, measured in kilograms.
,
- Initial and final speeds of the object, measured in meters per second.
Now, each speed is the magnitude of respective velocity vector:
Initial velocity
Final velocity
Finally, if ,
and
, then the work done by the force is:
The work done by the force is 820.745 joules.