Question

When a 100-N force acts horizontally on an 8.0-kg chair, the chair moves at a constant speed across the level floor. Which statement has to be true?

The chair accelerates at 12.5 m/s^2
The applied force is greater than the frictional force.
The friction force is 100 N
There is no friction between the floor and chair

Answer 1

The chair moving across a level floor at a constant speed with a 100-N force applied horizontally implies that the friction force opposing the movement is also 100 N, thereby resulting in no acceleration.

Step-by-step explanation:

When a 100-N force acts horizontally on an 8.0-kg chair and the chair moves at a constant speed across the level floor, it implies that the net force acting on the chair is zero. This is due to Newton's first law which states that an object will move at a constant velocity unless acted upon by an unbalanced external force. Since the chair moves at a constant speed, there is no acceleration, and thus the friction force must be equal to the applied force, which is 100 N. Therefore, the correct statement is that the friction force is 100 N.

Moreover, the equilibrium of forces in this scenario demonstrates that the static friction force between the chair and the floor precisely counteracts the applied horizontal force, resulting in a net force of zero. This balance ensures the chair's steady motion at a constant speed across the level floor.

Answer 2

The applied force is greater than the frictional force.

Step-by-step explanation:

the chair moves at a constant speed therefore, the answer is not A or C.

if there is no friction then the chair would accelerate and it would not be at a constant speed.

hence, the only possible answer is B.