Answer:
options A and C
Explanation:
Since, the spheres are of same size and rotational speed of the sphere are not dependent on their masses. So, both the sphere will reach the bottom of the at the same time with the same speed. But their kinetic energies are different.
So, options A and C are correct.
Answer:
500 J
Explanation:
In the case of a rectilinear movement, the work is calculated as the product of Force (N) * movement (m). In your case, unless the angle between the force vector and the displacement vector is different from 0, the work is:
25 N * 20 m = 500 J
Answer:
Explanation:
mass, m = 1 kg
Position (2, 3 ) m
height, h = 2 m
acceleration due to gravity, g = 9.8 m/s^2
Here, no force is acting in horizontal direction, the force of gravity is acting in vertical direction, so the work done by the gravitational force is to be calculated.
Force mass x acceleration due to gravity
F = 1 x 9.8 = 9.8 N
Work = force x displacement x CosФ
Where, Ф be the angle between force vector and the displacement vector.
Here the value of Ф is 180° as the force acting vertically downward and the displacement is upward
So, W = 9.8 x 2 x Cos 180°
W = - 19.6 J
Thus, option (A) is correct.
We can use the formula of the moment of inertia given by:

Where:
r = Distance from the point about which the torque is being measured to the point where the force is applied
F = Force
I = Moment of inertia
α = Angular acceleration
So:

Answer:
12 rad/s²