Question

A uniform disc of mass 100g has a
diameter of 10 cm. Calculate the total
energy of the disc when rolling along a
horizontal table with a velocity of 20 cms^-1
(take the surface of table as reference)​

Answer 1

Explanation:

please follow me

thanks

Answer 2

Total energy of the disc when rolling 0.001 J

Given:

Mass = m = 100 g = 0.1 kg

Diameter = d = 10 cm = 0.1 m

Radius = r = 0.05 m

Velocity = u = 20 cm/s = 0.2 m/s

Solution:

The kinetic energy is given by the formula:

K.E = 1/2 Iω²

Where,

I = Moment of inertia

ω = Angular acceleration

The angular acceleration is given by the formula:

ω = v/r

On substituting the values, we get,

ω = 0.2/0.05 = 4 rad/s

I = mR²/2

On substituting the values, we get,

I = (0.1 × 0.05 × 0.05)/2 = 1/8000

Now, the kinetic energy is given as:

K.E = 1/2 × 1/8000 × 16

∴ K.E = 0.001 J