Efficiency = useful energy out / total energy in x 100
= 100/400 x 100
=0.25 x 100
= 25%
25%
The height of the tennis ball,relative to the ground is H=h max+h-->h max-the maximum height that the tennis ball reaches relative to the roof of the building; h-the height of the building;h max =v0^2/2g=24,2m(g=10m/s^2).H=gt^2/2=>24,2+h=gt^2/2=>h=gt^2/2-24,2=180,6m
Using the addition of forces using right angled triangles. The resultant force sqaured. = 112.8 sqaured + 52.6 squared. So resultant force sqaured is 15490.6. So the resultant force is the sqaure root of this which is 124N to 3 significant figures
Answer:
(a) 1.093 rad/s^2
(b) 4.375 rad/s
(c) 8.744 rad/s
(d) 67.845 rad
Explanation:
initial angular velocity, ωo = 0
time, t = 8s
angular displacement, θ = 35 rad
(a) Let α be the angular acceleration.
Use second equation of motion for rotational motion

By substituting the values
35 = 0 + 0.5 x α x 8 x 8
α = 1.093 rad/s^2
(b) The average angular velocity is defined as the ratio of total angular displacement to the total time taken .
Average angular velocity = 35 / 8 = 4.375 rad/s
(c) Let ω be the instantaneous angular velocity at t = 8 s
Use first equation of motion for rotational motion
ω = ωo + αt
ω = 0 + 1.093 x 8 = 8.744 rad/s
(d) Let in next 5 seconds the angular displacement is θ.

By substituting the values
θ = 8.744 x 5 + 0.5 x 1.093 x 5 x 5
θ = 67.845 rad
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