Statics and Friction

A particle of mass 5 kg lies on a smooth plane inclined at an angle of 30° to the horizontal. The particle is prevented from sliding down the plane by a string parallel to the plane. The tension in the string is

• 24.5 N

• 42.4 N

• 2.5 N

• 4.33 N

From Question 1, the normal reaction force between the particle and the plane

A particle of mass 5 kg lies on a smooth plane inclined at an angle of 30° to the horizontal. The particle is prevented from sliding down the plane by a string parallel to the plane.

• 2.5 N

• 24.5 N

• 42.4 N

• 4.33 N

A particle of mass 4 kg is suspended in equilibrium from two strings of lengths 7 cm and 24 cm which are attached to two points 25 cm apart. The tensions in the strings are

• 19.7 N and 27.9 N

• 15.2 N and 36.5 N

• 17.8 N and 36.9 N

• 11.0 N and 37.6 N

A mass of 50 grams hangs in equilibrium on a string. The mass is pulled aside and upwards by a force of 0.3 N which makes an angle of 30º with the horizontal. The angle which the string makes with the vertical is

• 52.6°

• 37.4°

• 22.1°

• 67.9°

In question 4, the tension in the string is

A mass of 50 grams hangs in equilibrium on a string. The mass is pulled aside and upwards by a force of 0.3 N which makes an angle of 30º with the horizontal.

• 0.428 N

• 0.560 N

• 0.367 N

• 0.904 N

A horizontal force of 30 N applied to a mass of 8 kg is just enough to move the mass along a rough horizontal surface. What is the coefficient of friction between the mass and the surface?

• 0.27

• 2.61

• 3.75

• 0.38

A block of mass 5 kg rests on a rough plane inclined at 27° to the horizontal. A force of 35 N acts parallel to the plane, and the block is on the point of moving up the plane. What is the coefficient of friction between the block and the plane?

• 0.345

• 0.320

• 0.292

• 0.517

A mass of 5 kg is placed on a rough plane inclined at 25° to the horizontal. A force of 15 N, acting parallel to the plane, can just prevent the mass of 5 kg from sliding down the plane. The force is increased until the mass is on the point of sliding up the plane. The new value of the force is

• 26.4 N

• 56.4 N

• 35.7 N

• 73.8 N

In question 8, the value of the coefficient of friction is

A mass of 5 kg is placed on a rough plane inclined at 25° to the horizontal. A force of 15 N, acting parallel to the plane, can just prevent the mass of 5 kg from sliding down the plane. The force is increased until the mass is on the point of sliding up the plane.

• 0.129

• 0.466

• 0.600

• 0.254

A mass of 5 kg is on a rough slope inclined at 15° to the horizontal. The coefficient of friction is 0.2. The mass is attached to a light string, which makes an angle of 25° above the slope. The mass is just about to start to move up the slope. What is the tension in the string?

• 22.4 N

• 16.8 N

• 15.7 N

• 26.3 N