1. Force and Motion December 2014 Benchmark Review

2. Formula Triangle F=ma F=ma m=F/a a=F/m Use your finger to cover the value you are looking for. If the values you already have are next to each other, you multiply. If they are above and below each other, you divide.

3. Calculate the Mass for the object below (yes, I know it says acceleration on the paper) Force (N) Acceleration (m/s 2 ) 52.5 105 2010 3015 Mass = Force/Acceleration Force (N) Acceleration (m/s 2 ) Mass (Kg) 52.5 2 105 2 2010 2 3015 2

4. Formula Triangle S=d/t Use your finger to cover the value you are looking for. If the values you already have are next to each other, you multiply. If they are above and below each other, you divide.

5. Calculating Speed  Speed= 200,000 km/s  time=2 sec  distance= 400,000 km 200,000 km/s 2s2s

6. Speed Graph 9:30 to 10:00 Distance = 0 (object did not move) Time = 0.5 hr S=d/t S= 0km/.5hr = 0 km/hr

7. Speed Graph 10:00 to 11:00 Distance = 100km – 60km = 40 km Time = 1 hr S=d/t S= 40km/1hr = 40 km/hr

8. Speed Graph 10:00 to 12:00 Distance = 60km – 20km = 40 km Time = 2 hr S=d/t S= 40km/2hr = 20 km/hr

9. Speed Graph The object moves at a steady rate from 8:45 to 9:30. The object is then at rest for 30 minutes, then continues at a slower steady rate for 1 hour. The object stops briefly, then returns to the starting point at a faster steady rate.

10. Net Force Diagram  Draw a diagram which shows an object being pushed to the right with a force of 6 newtons and to the left with a force of 3 newtons. Which way will the object move? Will the object’s speed increase, decrease, or remain constant? 6N 3N The object will accelerate (move with increasing speed) to the right because the greater force is pushing to the right.

11. How does the force of an object affect the object’s speed? The more force that is applied to an object, the fast it will go. (Newton’s 2 nd Law)

12. Distance / Time Graph Type of LineIncrease or Decrease or Constant Constant Speed No Change in Motion Constant Speed

13. Velocity / Time Graph Type of LineIncrease or Decrease or Constant Increase Speed Constant Speed Decrease Speed

14. Balanced Forces Net Force = 0 If forces are BALANCED then there is no change in motion.

15. Unbalanced Forces Net Force= >0 If forces are UNBALANCED, then there is a change in motion. The object will accelerate in the DIRECTION of the GREATER force. Net Force = 3N to the right

16. Newton’s 1 st Law  Law of Inertia  An object at rest stays at rest and an object in motion stays in motion unless acted upon by an unbalanced force.  When a car stops suddenly, your body wants to continue to move forward until an outside force (hopefully a seat belt) stops it

17. Newton’s 2 nd Law  F=ma  The acceleration of an object is dependent upon two variables – the net force acting upon the object and the mass of the object.  A rock with a larger mass will require more force to move.

18. Newton’s 3 rd Law  Action / Reaction  For every action there is an equal and opposite reaction  A rockets thrust goes downward to push the rocket upward