Answer:
5) 13 revolutions (approximately)
Explanation:
We apply the equations of circular motion uniformly accelerated :
ωf²= ω₀² + 2α*θ Formula (1)
Where:
θ : angle that the body has rotated in a given time interval (rad)
α : angular acceleration (rad/s²)
ω₀ : initial angular speed ( rad/s)
ωf : final angular speed ( rad/s)
Data:
ω₀ = 18 rad/s
ωf = 0
α = -2 rad/s² ; (-) indicates that the wheel is slowing
Revolutions calculation that turns the wheel until it stops
We apply the formula (1)
ωf²= ω₀² + 2α*θ
0 = (18)² + 2( -2)*θ
4*θ = (18)²
θ = (18)²/4 = 81 rad
1 revolution = 2π rad
θ = 81 rad * 1 revolution / 2πrad
θ = 13 revolutions approximately
According to the right-hand thumb rule, the forefinger gives the velocity of charge, the thumb gives the magnetic force and the center finger gives the direction of magnetic field.
then, as shown in the picture, the <span>direction of the magnetic force on the charge is in the right direction.</span>
The formula for speed is distance÷time. The distance in this situation is 27km and the amount of time taken to cover that distance is 5 hours. Now, we substitute the values into an equation:
Speed = 27km/5h
Speed = 5.4km/h
Therefore, Desmond's speed is 5.4km/h.
The answer would B, trust me it’s right
I think that the downstairs would be faster because the water wouldn't have to go all the way up which make it slower
