Answer:
225 rpm
Explanation:
The angular acceleration of the fan is given by:

where
is the final angular speed
is the initial angular speed
is the time interval
For the fan in this problem,

Substituting,

Now we can find the angular speed of the fan at the end of the 5th second, so after t = 5 s. It is given by:

where

Substituting,

Answer: 1026s, 17.1m
Explanation:
Given
COP of heat pump = 3.15
Mass of air, m = 1500kg
Initial temperature, T1 = 7°C
Final temperature, T2 = 22°C
Power of the heat pump, W = 5kW
The amount of heat needed to increase temperature in the house,
Q = mcΔT
Q = 1500 * 0.718 * (22 - 7)
Q = 1077 * 15
Q = 16155
Rate at which heat is supplied to the house is
Q' = COP * W
Q' = 3.15 * 5
Q' = 15.75
Time required to raise the temperature is
Δt = Q/Q'
Δt = 16155 / 15.75
Δt = 1025.7 s
Δt ~ 1026 s
Δt ~ 17.1 min
The direction in which the magnetic force is acting on the charge is upwards.
<h3>What is Magnetic force?</h3>
This is the attraction and repulsion which usually occurs during the motion of electrically charged particles.
In the magnetic field, the charge is moving to the left. Therefore the direction the magnetic force is acting on the charge is upwards which is gotten via right hand rule.
Read more about Magnetic force here brainly.com/question/25932320
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