Forces & Dynamics Unit Pre-assessment: Objective 1 - Types of Forces

Ready for physics? This pre-assessment challenges students on **types of forces**, motion, and force diagrams! Perfect for grades 8-9.

1. A surfer paddles out from shore in search of the perfect wave. The surfer has a weight of 500 N and the surfboard weighs 100 N. Calculate the buoyant force pushing up on the board when the surfer is on a surfboard floating on calm water. Are the forces balanced or unbalanced? 100 Newtons 400 Newtons 500 Newtons 600 Newtons The forces are balanced The forces are unbalanced 2. Analyze the diagram and infer which colored arrows and direction of the interacting force pairs represent tension forces: BLUE - the tension forces are the PULLING forces BLUE - the tension forces are the PUSHING forces RED - the tension forces are the PULLING force RED - the tension forces are the PUSHING forces 3. Analyze the diagram and infer the relationship between the compression and tension forces on the Suspension and Cable-stayed bridge design:Predict what could happen to these long bridges if the cables or trusses were not present on the bridge. SELECT ALL THAT APPLY The cables push down on the bed of the bridge to prevent upheaval The cables pull up on the bed of the bridge to prevent collapse Without the cables the bridge would not be able to be as long the distance it needs to. The cables are just decorative. The forces are balanced in solely in the bed of the bridge to offer stability 4. A student pushes a book across a classroom table. Which of the following statements best explains the difference between the amount of force needed to start the book moving and the amount of force needed to keep it moving? SELECT ALL THAT APPLY Less force is needed to start the book moving, because there is less friction than when it is already moving. More force is needed to start the book moving, because there is more friction than when it is already moving. More force is needed to start the book moving, because there is more potential energy in the table than in the book. Less force is needed to start the book moving, because there is less potential energy in the table than in the book. The magnitude of static friction is greater than kinetic friction The magnitude of kinetic friction is greater than static friction The magnitude of static friction and kinetic friction is equal The magnitude of the PE before the object moves is greater than while it is moving The magnitude of the PE after the object moves is greater than while it is moving The magnitude of the PE is the same before and after the book moves 5. The force of gravity on the surface of the moon is about one-sixth the force of gravity on the surface of Earth. Which describes the relationship of mass and weight of an object on the moon compared to that on Earth? Are mass and weight forces? SELECT ALL THAT APPLY Both mass and weight are greater on the moon. Both mass and weight are less on the moon. Mass is the same, but weight is less on the moon. Weight is the same, but mass is less on the moon. Weight is a force Mass is a force Neither Weight or Mass are forces 6. Calculate the mass of an object weighing 63 N on Earth. 0.16 kg 6.4 kg 73 kg 617 kg 7. Which diagram best shows forces acting on an object that is sitting at rest on a table? Are the forces balanced or unbalanced? The forces are balanced The forces are unbalanced 8. In the diagrams below, g is the force of gravity, r, is the force of the ramp acting on the car and, f, is the force of friction.Which diagram shows the directions of the forces acting on a car as it travels down the ramp? Are the gravitational forces and force of the ramp on the car balanced or unbalanced? Will the car move down the ramp at a constant speed or will it be speeding up? g and r are balanced g and r are unbalanced the car will move at a constant speed down the ramp the car will speed up as it travels down the ramp 9. Categorize and classify the following as contact forces, noncontact forces, and not a force. Contact Force Friction Air Resistance Applied Force Tension Compression Normal Force Buoyant Force Noncontact Force Weight Gravity Magnetic Force Electrical Force Not a Force Mass Gravitational Potential Energy Density