Physics - Study Mode

[#1091] A sphere rolls down on two inclined planes of different angles but same height, it does so
Correct Answer

(B) With the same speed

Explanation

Solution: A solid sphere rolls down two different inclined planes of the same height but of different inclinations. The speed and the of descend will be same.

[#1092] If a body moves with a constant speed in a circle
Correct Answer

(D) Its velocity remains constant

Explanation

Solution: If a body moves with a constant speed in a circle its velocity remains constant.

[#1093] A disk and a sphere of same radius but different masses roll on two inclined planes of the same altitude and length. Which one of the two objects gets to the bottom of the plane first ?
Correct Answer

(B) Sphere

Explanation

Solution: The sphere will reach the bottom faster than the disk. It is because the disk has a higher rotational inertia than the solid: I= mr² I is the rotational inertia where m is the mass and r is the square of distance from the axis of rotation. in the case of disk I is greater due to r and more the I, more is the rotational K.E. Then for conservation of energy Translational K.E will be less. mgh= K.E (T) + K.E (R) so in case of sphere translational K.E will be more, meaning more final velocity and it will reach the bottom faster.

[#1094] The washing machine works on the principle of
Correct Answer

(D) Centrifugation

Explanation

Solution: A washing machine by spinning at 800-1600 rpm helps soap and dirt with it to leave the surface of the cloth via centrifugal force and into outlet pipes hence utilizing centrifugation to both clean and partially dry the clothes loaded in it.

[#1095] When an unbalanced force acts on an object
Correct Answer

(D) All of the above

Explanation

Solution: When an unbalanced force acts on an object it causes change in motion of the object, the speed and direction of the object changes and the object moves.