Effects of forces on speed and direction Knowledge-Based Practice

Questions

1. 1.

   A sled moves across a frictionless, level surface in a straight line. If a constant nonzero net force acts on the sled in the exact direction of its motion, how are its speed and direction affected?

   • A) Its speed increases, and its direction of motion remains unchanged.
   • B) Its speed decreases, and its direction of motion remains unchanged.
   • C) Its speed remains constant, and its direction of motion curves.
   • D) Both its speed and its direction of motion remain completely unchanged.
2. 2.

   A toy car moves eastward in a straight line across a level surface. A constant net force is exerted on the car directed toward the west. Which statement correctly describes the car's speed and direction of motion before it comes to a momentary stop?

   • A) Its speed increases while its direction of motion remains eastward.
   • B) Its speed remains constant while its direction of motion shifts northward.
   • C) Both its speed and its direction of motion change continuously.
   • D) Its speed decreases while its direction of motion remains eastward.
3. 3.

   An object moves along a flat, frictionless surface. If a continuous net force acts perpendicular to the object's direction of motion at every instant, how are its speed and direction affected?

   • A) Its speed increases while its direction remains unchanged.
   • B) Its speed decreases while its direction remains unchanged.
   • C) Both its speed and its direction change simultaneously.
   • D) Its direction changes while its speed remains constant.

Answers and step-by-step solutions appear after you finish the test.