Normal force Knowledge-Based Download PDF

Questions

1. 1.

   A 4.0 kg block rests on a horizontal floor. A vertical rope pulls upward on the block with a constant tension of 50 N. Taking the acceleration due to gravity to be 10 m/s², what is the magnitude of the normal force exerted by the floor on the block?

   • A) 10 N
   • B) 0 N
   • C) 40 N
   • D) 90 N
2. 2.

   A 20 kg crate rests on the flat horizontal floor of a train car that accelerates horizontally along a straight track at 4.0 m/s². Taking the acceleration due to gravity to be 10 m/s², what is the magnitude of the normal force exerted by the floor on the crate?

   • A) 80 N
   • B) 200 N
   • C) 215 N
   • D) 120 N
3. 3.

   A book rests motionless on a flat horizontal table. According to Newton's third law of motion, which force forms the action-reaction pair with the normal force exerted by the table on the book?

   • A) The downward contact force exerted by the book on the table
   • B) The downward gravitational force exerted by the Earth on the book
   • C) The upward gravitational force exerted by the book on the Earth
   • D) The downward normal force exerted by the table legs on the floor
4. 4.

   A 4.0 kg block and a 2.0 kg block are placed in contact on a frictionless horizontal floor. If a constant horizontal force of 18 N pushes the 4.0 kg block toward the 2.0 kg block, what is the magnitude of the normal contact force exerted by the 4.0 kg block on the 2.0 kg block?

   • A) 18 N
   • B) 12 N
   • C) 9.0 N
   • D) 6.0 N
5. 5.

   A student pushes a 1.5 kg textbook vertically upward against a flat horizontal ceiling with a constant force of 25 N. Taking the acceleration due to gravity to be 10 m/s², what is the magnitude of the normal force exerted by the ceiling on the textbook?

   • A) 10 N
   • B) 15 N
   • C) 25 N
   • D) 40 N
6. 6.

   A 3.0 kg box rests on top of a 5.0 kg box that sits on a flat, horizontal floor. Taking the acceleration due to gravity to be 10 m/s², what is the magnitude of the normal force exerted by the floor on the 5.0 kg box?

   • A) 80 N
   • B) 50 N
   • C) 30 N
   • D) 20 N
7. 7.

   A person holds a 2.0 kg book at rest against a vertical wall by applying a horizontal pushing force of 35 N directly toward the wall. Taking the acceleration due to gravity to be 10 m/s², what is the magnitude of the normal force exerted by the wall on the book?

   • A) 15 N
   • B) 20 N
   • C) 35 N
   • D) 55 N
8. 8.

   A 5.0 kg crate slides down a frictionless ramp inclined at 37° to the horizontal. Given that the acceleration due to gravity is 10 m/s², sin 37° = 0.60, and cos 37° = 0.80, what is the magnitude of the normal force exerted by the ramp on the crate?

   • A) 40 N
   • B) 50 N
   • C) 30 N
   • D) 24 N
9. 9.

   A 12 kg crate rests on the floor of an elevator that accelerates upward at a rate of $2.5\text{ m/s}^2$. Taking the acceleration due to gravity to be $10\text{ m/s}^2$, what is the magnitude of the normal force exerted by the floor on the crate?

   • A) 30 N
   • B) 90 N
   • C) 120 N
   • D) 150 N
10. 10.

    A 6.0 kg block rests on a horizontal floor while a 20 N tension force pulls on it at an angle of 30° above the horizontal. Taking the acceleration due to gravity to be 10 m/s², what is the magnitude of the normal force exerted by the floor on the block?

    • A) 40 N
    • B) 50 N
    • C) 60 N
    • D) 70 N