Engineering Mechanics- Friction

What is the definition of friction?

• A force that repels objects

• A force that keeps objects stationary

• A force that causes objects to slow down

• A force that causes objects to move faster

What are the two types of friction?

• Dry and Wet

• Coulomb and Fluid

• Normal and Tangential

• Static and Kinetic

What is the coefficient of friction for a wooden cube resting on a horizontal plane?

• 0.3

• 0.4

• 0.2

• 0.1

What is the angle of friction when no friction is present?

• 45 degrees

• 30 degrees

• 0 degrees

• 60 degrees

A uniform wooden cube of side 1 m and weighing 5000N rest on its side on a horizontal plane. Find the maximum horizontal force can be applied at the top edge of cube to make it slide without overturning.

• 1500N

• 1250N

• 1750N

• 1000N

What is the angle of repose?

• Angle at which a body starts moving

• Angle at which a body can repose without external force

• Angle at which a body overturns

• Angle at which a body slides

Two wedges A and B are used to raise another block C weighing 1000 N as shown in fig. Assuming coefficient of friction as 0.25 for all the surfaces, determine the value of P for impending upwards motion of block C.

• 6008.46 N

• 608.46N

• 304.23 N

• 500 N

Draw the freebody diagram of the inclined block with the inclinaton of 30 deg and weighing 100 N.

A uniform ladder 5 m long, weighing 250 N, is placed against a smooth vertical wall with its lower end 2 m from the wall. The coefficient of friction between the ladder and floor is 0.25. Show that the ladder will remain in equilibrium in this position.

The angle of friction is defined as the angle made by the _________of the ____________ and the

limiting force of friction (F) with the normal reaction (R).