well thanks for the Information
Answer:
Approximately
, assuming that 
Explanation:
The weight of the elevator is:
.
Since the speed of the elevator is constant, the acceleration of this elevator would be
.
By Newton's Second Law of Motion, the net force on the elevator (proportional to acceleration) would also be
. All external forces on the elevator need to be balanced in every direction.
The only two vertical forces on the elevator are:
- the weight of the elevator (downward gravitational pull from the earth,) and
- the upward pull from the motor.
These two forces need to balance one another. Since the weight of the elevator is approximately
, the upward pull of the motor would be
. in magnitude.
The direction of this upward pull is the same as the direction of the motion of this elevator. Thus, the work that the motor did on the elevator would be positive:
.
Since the velocity of the elevator is constant, instantaneous power output of the motor would be equal to the average power of the motor:
.
Answer:
The conditions necessary for hearing the echo. The distance between the sound source and the reflecting surface must not be less than 17 metres where the time period between hearing the original sound and its echo should not be less than 0.1 of a second.
Answer:
P = 173.33 [W]
Explanation:
Power is defined as the amount of work done over a given time.
W = work = 520 [J]
t = time = 3 [s]
P = power [w]
Therefore by working relationship over time we can calculate the power.
![P =W/t\\P = 520/3\\P=173.33[W]](https://tex.z-dn.net/?f=P%20%3DW%2Ft%5C%5CP%20%3D%20520%2F3%5C%5CP%3D173.33%5BW%5D)