Forces and Motion Study Guide

Net Force, Balanced and Unbalanced Forces

  1. What is the combination of all forces working on an object called?
  1. What will knowing the net force on an object tell you about the forces on an object?
  1. What will knowing the direction of the net force tell you about the forces on an object?
  1. If you have a net force that is equal to zero, what can you infer about the object?
  1. If you have a net force that is equal to a number greater than zero, what can you infer about that object?
  1. A tug boat is pulling a barge against a current with 375 Newtons of force and the current is pushing the barge with 130 Newtons of force. What is the total net force? Is the force of the barge balanced or unbalanced? Is the tugboat doing work? Explain.
  1. A soccer ball is motionless on the soccer field and a penalty kick is about to take place. The player kicks the ball and the goalie knocks the ball out of the net and the ball rolls until it stops. Explain how balanced and unbalanced forces are being applied to the ball during this scenario. Also explain how velocity and acceleration are applied to the ball.
  1. In a tug of war, one team is pulling with a force of 230N to the left and the other team is pulling with 280 N to the right. What is the net force? Why?
  1. Describe one major force that keeps objects balanced.
  1. Vectors - Draw 3 vectors on the grid below as directed:
  2. 6 Newtons of force down
  3. 10 Newtons of force to the left
  4. 3 Newtons of Force up and 4 Newtons of force down
  1. For the pictures below, provide the net force, whether the forces are balanced or unbalance and the direction for the object.
  1. Two tugboats are moving a barge. The 1stTugboat exerts a force of 3000 newtons on the barge. The 2ndTugboat exerts a force of 5000 newtons in the same direction.
  2. Draw arrows showing the individual forces of the tugboats.
  1. What is the net force being exerted on the barge?
  1. Are the forces balanced or unbalanced?
  1. Now suppose that the 1st tugboat exerts a force of 2000 newtons on the barge and the 2nd tugboat exerts a force of 4000 newtons in the opposite direction.
  2. Draw arrows showing the individual forces of each tugboat.
  1. What is the combined net force?
  1. Are the forces balanced or unbalanced?
  1. Could there ever be a case when the 1st and 2nd tugboat both exert a force on the barge but the barge does not move? Explain.
  1. Explain the motion of a balanced object.
  1. Graph the motion of a jogger that has ran at a constant rate of speed going a distance of 275km in 30 minutes.
  1. What would the graph look like if the jogger stopped and rested?
  1. What is the average speed of the jogger?
  1. Delta flight 263 is flying South at 379 mph and starts it’s landing preparations which requires the plane to travel at 215mph. What is the acceleration of the plane? Calculate and explain.
  1. A car is traveling at a speed of 79 mph to the West and increases its speed to 85 mph. Does the velocity of the car change? Explain.
  1. A bike rider is traveling in France and wants to break his previous time record of 2.5 hours. He travels an average of 41mph for a distance of 270km. Did he break his previous record?