Answer:
(a) The final angular speed is 12.05 rad/s
(b) The time taken to turn 5.5 revolutions is 5.74 s
Explanation:
Given;
number of revolutions, θ = 5.5 revolutions
acceleration of the wheel, α = 20 rpm/s
number of revolutions in radian is given as;
θ = 5.5 x 2π = 34.562 rad
angular acceleration in rad/s² is given as;
(a)
The final angular speed is given as;
(b) the time taken to turn 5.5 revolutions is given as
Answer:
The increase in potential energy of the ball is 115.82 J
Explanation:
Conceptual analysis
Potential Energy (U) is the energy of a body located at a certain height (h) above the ground and is calculated as follows:
U = m × g × h
U: Potential Energy in Joules (J)
m: mass in kg
g: acceleration due to gravity in m/s²
h: height in m
Equivalences
1 kg = 1000 g
1 ft = 0.3048 m
1 N = 1 (kg×m)/s²
1 J = N × m
Known data
Problem development
ΔU: Potential energy change
ΔU = U₂ - U₁
U₂ - U₁ = mₓgₓh₂ - mₓgₓh₁
U₂ - U₁ = mₓg(h₂ - h₁)
The increase in potential energy of the ball is 115.82 J