Answer:
Explanation:
Let T be the tension
For linear motion of hoop downwards
mg -T = ma , m is mass of the hoop . a is linear acceleration of CG of hoop .
For rotational motion of hoop
Torque by tension
T x R , R is radius of hoop.
Angular acceleration be α,
Linear acceleration a = α R
So TR = I α
= I a / R
a = TR² / I
Putting this value in earlier relation
mg -T = m TR² / I
mg = T ( 1 + m R² / I )
T = mg / ( 1 + m R² / I )
mg / ( 1 + R² / k² )
Tension is less than mg or weight because denominator of the expression is more than 1.
The work-energy principle states that an increase in the kinetic energy of a rigid body is caused by an equal amount of positive work done on the body by the resultant force acting on that body. Conversely, a decrease in kinetic energy is caused by an equal amount of negative work done by the resultant force.
Answer:
8. acceleration = 
= 1 unit .
9. acceleration = = -1 unit.
10. acceleration = = 0 units.
Explanation:
8. i) acceleration = velocity / time
ii) In this figure velocity = time
iii) therefore acceleration = = 1 unit .
9. i) acceleration = velocity / time
ii) In this figure 4 = m + 5, therefore m = -1
therefore velocity = (-0.5 
time) + 5
iii) therefore acceleration = = -1 units.
10.) velocity is constant at 2
therefore acceleration = = 0 units
