Answer:
Explanation:
a ) Time period T = 2 s
Angular velocity ω = 2π / T
= 2π / 2 = 3.14 rad /s
Initial moment of inertia I₁ = 200 + mr²
= 200 + 25 x 2.5²
=356.25
Final moment of inertia
I₂ = 200 + 25 X 1.5 X 1.5
= 256.25
b ) We apply law of conservation of momentum
I₁ X ω₁ = I₂ X ω₂
ω₂ = I₁ X ω₁ / I₂
Putting the values

ω₂ = 4.365 rad s⁻¹
c ) Increase in rotational kinetic energy
=1/2 I₂ X ω₂² - 1/2 I₁ X ω₁²
.5 X 256.25 X 4.365² - .5 X 356.25 X 3.14²
= 684.95 J
This energy comes from work done against the centripetal pseudo -force.
Answer:
Option D. 1000 J.
Explanation:
From the question given above, the following data were obtained:
Force (F) applied = 200 N
Distance (s) = 5 m
Time (t) = 10 s
Workdone (Wd) =?
Workdone (Wd) is simply defined as the product of force (F) and distance (s) moved in the direction of the force. Mathematically, it is expressed as:
Wd = F × s
With the above formula, we can calculate the Workdone as illustrated below:
Force (F) applied = 200 N
Distance (s) = 5 m
Workdone (Wd) =?
Wd = F × s
Wd = 200 × 5
Wd = 1000 J
Thus, the Workdone is 1000 J