G9.docx

I. MULTIPLE CHOICE. Encircle the letter of the correct answer. 1. Which of the following is a scalar quantity? a. Weight b. Velocity c. Acceleration d. mass 2. Resultant can be described as_______? a. The product of vectors c. The sum of vectors b. The average of vectors d. The difference of vectors 3. At what quadrant is the opposite vector of X= 23 km, 64°, north of east located? a. I b. II c. III d. IV 4. The curve or parabolic path of a projectile is known as ______? a. Trajectory b. Projectile c. Zag d. line 5. What happens to the horizontal velocity of a projectile as it goes up? a. It becomes zero c. It decreases b. It remains the same d. It increases 6. What happens if your throw a ball vertically upward? a. slows down b. accelerate d. constant speed d. increase speed 7. What is the acceleration of a projectile when it reaches its highest point? a. 0 b. 9.8 m/s2 c. -9.8 m/s2 d. Less than 9.8 m/s2 8. Which of the following angles of release of a projectile, when it is fired at the same initial speed, gives the longest range? a. 10° b. 40° c.70° d.90° 9. Which of the following angles of release of a projectile, when it is fired at the same initial speed, has the highest point of trajectory? a. 10° b. 40° c.70° d.90° 10. A ball is fired at ang angle of 15° above the horizontal. At what angle shoud it be fired with the same speed in order to land at the same point? a. 0° b. 75° c. 90° d. 105° 11. You throw a ball in a 90° angle above horizontal, where do you think the ball will land? a. 10m away b. 5m away c. 90m away d. on the same spot For questions 9-10. A projectile is fired at an agle above the ground. It lands on the ground 6 seconds later. 12. At what time will the projectile reach its highest point of trajectory? a. Less than 6 s b. More than 3 s c. 3 s d. Less than 3 s 13. At what angle should the projectile be fired to have a maximum range? a. 0° b. 40° c. 90° d. 180° 14. Which of the following has the least intetia? a. pingpong ball b. Car d. Train d. basketball 15. Which of the following held at same speed has a greater momentum? a. A man running b. A man cycling c. Motorcycle d. Van 16. It is the product of mass and velocity? a. Momentum b. Impulse c. Gravity d. Acceleration 17. A 150 kg car is moving uniformly at a speed of 22 m/s. What is the momemtum of the car? a. 3,300 kg-m/s b. 6.7 kg-m/s c. 0.14 kg-m/s d. 2,300 kg m/s 18. Which of the following quantities is not present in a moving object? a. Acceleration b. Potential energy c. Impulse d.momemtum 19. An objecti is moving with inital speed. If its speed is tripled, what will happen to its momentum?

a. Its momentum is 1/3 of its initial momentum b. Its momentum becomes zero c. Its momemtum is also tripled d. Its momemtum is six time its initial momentum 20. If we decrease the mass of an object in half, what will happen to its speed? a. Will also decrease in half b. Will increase in half c. Will become zero d. Remains the same 21. You push wuth a force of +F on an stationary object in a period of time T. What will happen to the momentum of the object? a. Its momentum decreases in the positive direction b. Its momentum remains the same c. Its momentum increases im the positive direction d. Its momentum incrases in the negative direction 22. What will happen the force of impact if we extend the time of impact? a. It increase the force of impact b. It remains remains the same c. It will have a shorter time of impact d. It reduces the force of impact 23. The product of force and time is called? a. Momentum b. Impulse c. Gravity d. Acceleration 24. While a box is moving to the rightm a constant force of 50 N is apllied on it to the left in 2 seconds. What is the impulse of this force on the box? a. 25 N-s b. 50 N-s c. 100 N-s d. 2 N-s 25. What happen to the impulse if we shorten the time of impact? a. Increase b. Decrease c. Remains the same d. Becomes zero II. PROBLEM SOLVING. To receive credit be sure to: Identify Knowns/Unknowns, Write the Formula, show your solution and box the answer with correct units 1. Draw a cartesian plane and locate the following vectors: ( 2 points each) a. A = 10m, 45° east of south b. B = 18 m, north c. C = 12 m, 75° west of north

2. Find the resultant vector on #1 using x and y component method (10 points) Vector

Horizontal component (X)

Vertical component ( Y)

A B C R

Rx =

Resultant vector (R) =

Ry=

Note: 𝑅 = √𝑅𝑥 2 + 𝑅𝑦 2 3. In the given picture below, Alice throws the ball to the +X direction with an initial velocity 10m/s. Time elapsed during the motion is 5s. a. calculate Vy component of the velocity after it hits the ground. (5 points)

b. calculate the height that object is thrown. ( 5points)

4. A 125 kg motorcycle is moving at 50 m/s. a. Find its momentum ( 2 points)

b. At what velocity is the momentum of a 150 kg car equal to that of the motorcycle? ( 2pts)

5. Explain the importance of parachute in relation to our discussion in impulse and momentum? ( 5 points)