SPH 4U Kinematics Review Name
(assume ag = 9.8 m/s2 in all questions unless otherwise stated)
Part A – These Multiple Choice questions were from a previous test (answers have been removed)
1. An object is thrown vertically upward with a speed of 25 m/s. How much time passes before it comes back down at 15 m/s? (Air resistance is negligible.) (4.1 s)
2. The area under a velocity : time graph represents… (displacement)
3. A car has an initial velocity of 20 m/s [N] and a later velocity of 20 m/s [E]. The direction of the car’s acceleration will be… (SE)
4. Sketch the velocity-time graph of a car that pulls away from a corner when the light turns green, reaches and maintains a constant velocity, then slows down until it stops. Assume that all accelerations are uniform. (trapezoid)
5. An object is travelling due east when it experiences a uniform acceleration directed north. Its velocity some time later will be in which direction? (NE)
6. A football player successfully kicks a field goal through the uprights situated at the south end of the stadium. What are the directions of the instantaneous velocity and acceleration, respectively, of the football at the peak of its trajectory? (v south; a down)
7. For a projectile returning to level ground, as the angle of projection increases from 0° to 45°, what will happen to the projectile’s time of flight and horizontal range? (both increase)
8. A firefighter, 50.0 m away from a burning building, directs a stream of water from a ground level fire hose at an angle of 30.0° above the horizontal. If the speed of the stream as it leaves the hose is 40.0 m/s, at what height will the stream of water strike the building? (18.7 m)
9. A projectile is fired from ground level such that it has an initial vertical speed of 20 m/s and an initial horizontal speed of 30 m/s. how far from the point of firing does the projectile land? Assume the terrain is flat, neglect air resistance, and take g = 10 N/kg. (120 m)
10. A dart is thrown horizontally toward target X with a speed of 20 m/s. It hits point Y below the target, 0.1 s later. The distance XY will be approximately (0.049 m)
11. A projectile of mass M and another of mass 5M were launched at the same time at 15o and 75o with respect to the ground, at the same speed. What can be said about their times aloft, their speeds upon impact with the ground and their ranges? (same ranges, same impact speeds; 75° = longer time)
12. If object A is in motion relative to object B, then what is B’s motion relative to A and the Earth?
(B is moving relative to A; could be moving or not)
13. A plane must fly to a destination located due north from its departure point. A gentle wind is blowing from the south-west. What direction must the plane point to reach its destination? (NW)
14. A passenger is walking at 2.5 m/s toward the front of a train that is moving north at 35 m/s. What is the passenger’s velocity relative to the train? To the ground? (37.5 [N])
15. With no wind, a hot air balloon rises vertically at 4.0 m/s. With a wind blowing, the same balloon rises at an angle of 10.0° with the vertical. What is the wind speed? (0.71 m/s)
Part B – Short Answer and Problems
16. A fish swimming North at 2.1 m/s sees a shark coming towards it. Thinking quickly, he changes his velocity to 1.8 m/s [E 30º S]. What is his average acceleration if the manoeuvre took 0.6 s?
17. A ball rolls off a table and falls to the ground below. Its entire flight is captured on a stroboscopic photograph. Sketch what the photograph would look like if you viewed the motion with the ball initially moving to your right. Include vertical and horizontal velocity vectors for each position of the ball as viewed in the photograph.
18. a) An athlete executing a long jump leaves the ground at a 30° angle and travels 8.90 m. What was the takeoff speed?
b) What is the athlete’s maximum height during the jump?
19. An automobile traveling 90.0 km/h overtakes a 1.00 km-long train traveling in the same direction on a track parallel to the road. If the train’s speed is 66.0 km/h, how long does it take the car to pass it and how far will the car have traveled in this time? What are the results if the car and train are traveling in opposite directions?
20. Why do aircraft taking off from (or landing at) an airport fly into the wind?
21. Two cars approach the four-way stop where Algonquin Ave. meets Deep River Road. Car ‘A’ is heading north at 60 km/h and car ‘B’ is heading east at 40 km/h. What is the relative velocity of car ‘A’ to car ‘B’?
22. You are standing on top of the school with a snowball waiting to ambush your beloved physics teacher (must be a question from a different year). You are planning a high angle shot with an initial velocity of 20 m/s at 60°above the horizontal. The height of the school is 6.0 m.
a) What must be the horizontal displacement of your beloved physics teacher when you launch the snowball? (38 m)
b) What is the maximum height of the projectile above the launch level? (15.3 m)
c) With what velocity will the projectile impact? (22.4 m/s [63°below horizon])
23. An airplane is travelling 900 km/h in a direction 38.5° west of north.
a) Find the components of the velocity vector in the northerly and westerly directions.
b) How far north and how far west has the plane travelled after 3.00 h?
c) Where is the plane relative to where it began after 3.00 h? (2700 km [N38.5°W])
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