Semester 1 Physics Review 1. Differentiate between Speed and Velocity. The difference between speed and velocity is that speed is just the rate of movement. VELOCITY is SPEED an object moves AND the DIRECTION 2. Jose’s truck is stalled on a smooth flat road. 400 kg If a force of 200 Newtons is used to push the truck along the road, at what rate of acceleration will the truck move in m/sec2? A. B. C. D. 8000 m/sec2 2 m/sec2 0.5 m/sec2 5 m/sec2 f=ma so a=f/m a=200/400 a= 0.5m/sec2 3. How do icebergs near the polar icecap demonstrate Newton’s Law of Inertia? A. The iceberg will continue to move until it cracks from the pressure of the atmosphere. B. The iceberg will continue to move until it melts into the ocean water from the heat of the sun. C. The iceberg will continue to move until it returns to its original location. D. The iceberg will continue to move until it crashes into or slides against another iceberg. An object in motion will remain in motion at a constant velocity until acted upon by an outside force 4. The picture to the right shows sand dune in the desert, sand dunes change over time. The changes in the sand dunes occurred as the wind moves sand across the desert. Which type of energy is MOSTLY responsible for moving the sand? A. Kinetic energy – the energy of motion B. Radiant energy C. Potential energy D. Chemical energy 5. Megan and Jaime made a straw-balloon rocket, shown in the diagram below. They inflated the balloon, held the string tight and level, and watched the straw rocket move forward. Use Newton’s 3rd Law (Action-Reaction) to explain why the rocket moves forward. A. The string was too smooth The action is the air rushing B. The straw was taped to the top of the balloon out of the balloon and the C. The air rushing out of the balloon. reaction is the balloon rocket D. The air expanding the balloon’s volume moving forward 6. Which of the following vector diagrams shows two forces that are balanced? A. V B. C. D. Describe how you know that the forces in the vector diagram you selected are balanced. Both vector are the same size which indicates that the force is equal. They are applied in opposite directions. The forces cancel each other out and they are equal to a sum force of zero. Therefore the forces are balanced and the object will not move (or the motion will continue will constant velocity) 7. Work = Force X Distance Juan applies a force of 300 Newton’s to the first box for one minute, but the box did not move. He applies the same amount of force to a second box and the box moves 6 meters. What can you conclude about the work being done? A. 1800 Joules of work was done on box 1 and 0 Joules of work was done on box 2. B. 0 Joules of work was done on box 1 and 1800 Joules of work was done on box 2. C. 50 Joules of work was done on box 1 and 200 Joules of work was done on box 2. D. 0 Joules of work was done on box 1 and 100 Joules of work was done in box 2. In order for work to be done the object must move –box 1 did not move therefore 0 amount of work was done. Box 2 moved w=fxd w=300 X 6 w=1800 8. The graph below shows a bikes distance along a road at any given time what was the average speed of the bike? A. B. C. D. 0 km/hr 14 km/hr 2 km/hr 1 km/hr Average distance for the entire trip is taken from the final point on the graph S = d/t S= 14/14 S = 1 Use the information on the graph below to answer #9. D C B A 9. The graph shows the distance a bird flies over its migration period. Match the following statement with the section of the graph it describes. _D_ The bird flew slowest during this time interval. The slope is the least steep _B_ The bird stopped at a lake during this time interval. The line is flat horizontal _A_ The bird flew the fastest during this time interval. The line has the greatest slope