Applications of newton's law

It is more difficult to start moving a heavy couch

from rest than it is to keep pushing it with constant

velocity, because

• the normal force is greater when the

  couch is at rest

• the coefficient of kinetic friction is

  greater than the coefficient of static

  friction

• the coefficient of static friction is

  greater than the coefficient of kinetic

  friction

• there is no friction when the couch

  moves with constant velocity

A brick slides on a horizontal surface. Which of the

following will increase the magnitude of

the frictional force on it?

• Putting a second brick on top

• Decreasing the surface area of contact

• Increasing the surface area of contact

• Decreasing the mass of the brick

When a 12 N horizontal force is applied to a 6.0 N box on a horizontal tabletop,the box remains at rest. The force of static friction acting on the box is ______.

• 0.5N

• 2N

• 6N

• 12N

Which of the following correctly relates the normal force 𝐹_N, the tension 𝑇 and the total weight 𝐹_g

• F_N=F_g

• F_N= F_g + TSin𝜃

• F_N= F_g - TSin𝜃

• F_N= F_g - TCos𝜃

The magnitude of the frictional force in given diagram is

• T Sin𝜃

• T Cos𝜃

• mg Sin𝜃

• mg Cos𝜃

The vertical component of the force exerted on

the block by the floor is:

• mg

• 𝑚𝑔 − 𝑇𝑐𝑜𝑠𝜃

• 𝑚𝑔 − 𝑇 sin𝜃

• 𝑚𝑔 + 𝑇𝑐𝑜𝑠𝜃

A 2.0 kg bucket is lowered by a light rope with a

constant downward velocity of 3.0 m/s. What is the

tension in the rope?

• 6N

• 20N

• 30N

• 60n

What is the value of accelaration

• 12.5

• 5

• -25

• 8.3