Friction

A cyclist while negotiating a circular path with speed 20 m s^-1 is found to bend an angle by 30^o with vertical. What is the radius of the circular path?

(given, g = 10 m s^-2)

• 69.3 m

• 58.2 m

• 74.6 m

• 95.4 m

A body of weight W is resting on a frictional surface. The angle between the force of friction and the normal reaction is:

• 0⁰

• 30⁰

• 90⁰

• 180⁰

A cyclist is moving with a velocity v turns a circular path of radius r. His inclination with the vertical is given by:

• tan θ = v² / rg

• tan θ = v²g / r

• tan θ = v²rg

• none of the above

A cyclist going round in a circular track at a constant speed has:

• constant linear velocity

• constant linear velocity

• acceleration constant magnitude with its direction changing

• None of these

A body of mass m slides down a rough inclined plane of angle θ. The acceleration of the body at any instant is:

• g

• g sinθ

• g (sin θ + μ_k cos θ)

• g (sin θ - μ_k cos θ)

The body will move only when:

• Force of friction = applied force

• Force of friction < applied force

• Force of friction > applied force

• All of the above

Tags

NGSS.MS-PS2-2

A body slipping on a rough horizontal plane moves with a deceleration of 4.0 m/s². What is the coefficient of kinetic friction between the block and the plane? (g= 10 ms^-2)

• 0.5

• 0.2

• 0.6

• 0.4

When a body is moving on a surface, the force of friction is called:

• Static friction

• Dynamic friction

• Limiting friction

• Rolling friction

If μ_s, μ_k and μ_r are coefficients of static friction, sliding friction and rolling friction, then

• μ_s < μ_k < μ_r

• μ_k < μ_r < μ_s

• μ_r < μ_k < μ_s

• μ_r = μ_k = μ_s

A box is placed on an inclined plane and has to be pushed down. The angle of inclination is:

• Equal to angle of friction

• More than angle of friction

• Equal to angle of repose

• Less than angle of repose