A. same

**B. double**

C. half

D. four times

E. one fourth

# Engineering Mechanics

## Dynamic friction as compared to static friction is___________________?

A. same

B. more

**C. less**

D. may be less of more depending on nature of surfaces and velocity

E. has no correlation

## Friction force for dry surfaces. Friction force is________________?

Pick up wrong statement?

A. proportional to normal load between the surfaces

B. dependent on the materials of contact surface

**C. proportional to velocity of sliding**

D. independent of the area of contact surfaces

E. none of the above is wrong statement

## Which is the correct statement about law of polygon of forces ?

A. if any number of forces acting at a point can be represented by the sides

of a polygon taken in order, then the forces are in equilibrium

B. if any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon, then the forces are in equilibrium

C. if a polygon representing forces acting at a point is closed then forces are in equilibrium

**D. if any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon taken in order, then the forces are in equilibrium**

E. none of the above.

## If two equal forces of magnitude P act at an angle 9°, their resultant will be________________?

A. P/2 cos 9/2

B. IP sin 9/2

C. 2P tan 9/2

**D. IP cos 9/2**

E. Psin 9/2

## If a number of forces act simultaneously on a particle, it is possible _____________________?

A. not a replace them by a single force

**B. to replace them by a single force**

C. to replace them by a single force through C.G.

D. to replace them by a couple

E. to replace them by a couple and a force

## Which of the following is a vector quantity___________________?

A. energy

B. mass

**C. momentum**

D. angle

E. speed

## A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal_________________?

**A. density of metal can’t be determined**

B. metal is twice as dense as water

C. metal will float in water

D. metal is twice as dense as unknown fluid

E. none of the above

## A projectile is fired at an angle 9 to the vertical. Its horizontal range will be maximum when 9 is_______________?

A. 0°

B. 30°

**C. 45°**

D. 60°

E. 90°.

## The units of moment of inertia of mass are ________________?

**A. kg m2**

B. m4

C. kg/m2

D. kg/m

E. m2/kg