Review for Motion in a Plane Test

A.  Study the last tip sheet    B. Review last quiz    C. Review HW questions     D. Study notes

1. Remember the demo I did with two steel marbles? I put the marbles into a device that dropped one, and at the same time,  projected the other horizontally.  Do you remember what happened?

2. What angle of projection produces the greatest height? _____

greatest range?_____

3. In what direction do the force of gravity AND the acceleration due to gravity always act on a projectile? Draw this.

4. What is the name for the shape of a projectile path? Draw the shape.

5.  A projectile is fired at an angle of. The vertical velocity of the object is 10 m/s and the horizontal velocity is 20 m/s. How far will the object travel in 3 seconds?

6. Draw in the velocity, centripetal acceleration and centripetal force vectors for this object moving in a circle. (lots of questions on this)

7.  What are horizontal and vertical components of a projectile projected at an angle of 60 degrees and a velocity of 20 m/s?

Horizontal Component:                                            Vertical Component:

8. Know your centripetal acceleration and centripetal force plug-ins (see HW.)  a) An object with a speed of 2 m/s has an acceleration of 4 m/s2. What is the radius of the circle in which the object travels?

b) If an object with a mass of 2 kg and a velocity of 5 m/s travels in a circle with a radius of 2 m, how much force must be applied to this object to keep it its circular path?

9. Know your mathematical relationships. F = mv2/r

Which 2 variables show inverse? ________direct? ________direct square?____

b) What will happen to the centripetal force if you double m? ________ v? ________ r? ________

10. What is a geosynchronous satellite?

11. What is the orbital period of a geosynchronous satellite? (i.e. time for one revolution)

12. All things being equal, is the centripetal force and centripetal acceleration greatest in a small circle or large circle? What is this relationship called?

13. How do each of the following change when an object is dropped?

Vertical velocity _____ Horizontal velocity _____Vertical Acceleration _____Horizontal Accel. _____

14. How do each of the following change when an object is projected horizontally?

Vertical velocity _____Horizontal velocity _____Vertical Accel. _____Horizontal Accel. _____

15. How do each of the following change for a projectile heading toward the peak?

Vertical velocity _____Horizontal velocity _____Vertical Accel. _____Horizontal Accel. _____

16. How do each of the following change for a projectile moving past it's peak?

Vertical velocity _____Horizontal velocity _____Vertical Accel. _____Horizontal Accel. _____

17. A projectile has a vertical speed of 30 m/s and a horizontal speed of 10 m/s. Fill out this chart below.

 time(sec) Vx (m/s) Vy (m/s) 0 10 30

18. Is the acceleration due to gravity constant on the moon?

19. What does the plot of free fall look like on a d vs. t plot and a V vs. t plot?

20 . A bullet is fired straight upward. If the bullet leaves the gun at a speed of +1200 m/s, approximately what speed does it have when it returns to the ground?

21. An astronaut dropped a feather and a sledge hammer on the moon. What happened?

22. Why is the horizontal velocity of a projectile constant, while the vertical velocity constantly changes?