Lagos State University PHY 101 Kinematics Practice Questions PDF

BUNDAY TUTORIAL Lagos State University MR BUNDAY: 07011534711, 07053845576 PHY 101 PRACTICE QUESTIONS KINE...

BUNDAY TUTORIAL Lagos State University MR BUNDAY: 07011534711, 07053845576 PHY 101 PRACTICE QUESTIONS KINEMATICS EQUATIONS OF MOTION 1. A car experiences a displacement of 40km in 20min. What is its average velocity in m/s 2. A tennis player serves a ball with an average velocity of 160 km/hr. How long does it take the ball to go from one baseline to the other 12.00m away? 3. It takes a car 35 min to cover the first part of a journey, which is 55km long. The second part of the journey is 85 km and takes 55min. What is the average velocity for the entire journey? 4. A particle is moving along the x-axis such that its position is given by x = 3t2 − 16t + 8. What are the velocity and acceleration of the particle at t = 4s? At what time is the particle stationary 5. Compare your average speed in the following two cases: (a) You walk 120m at a speed of 1ms1 and then run 120m at a speed of 3ms1 along a straight track. (b) You walk for 1 minute at a speed of 1ms1 and then run for 1 minute at a speed of 3ms1 along a straight track. 6. A body starts from rest with an acceleration of 2ms−2. What velocity does it attain after 10 s? A. 20 m/s B. 10 m/s C. 15 m/s D. 12 m/s E. None of the above 7. A ball moving with an initial velocity of 5 m/s is accelerated uniformly at the rate of 4 m/s for 15 s in the same direction as it is moving before. Calculate the distance covered by the ball during the period for which it is accelerated A. 230 m B. 200 m C. 525 m D. 625 m E. None of the above 8. What is the length of a train which crosses a bridge of 150m in 20 sec with a speed of 40 km/hr? A. 222 m B. 150 m C. 72.2 m D. 70.5 m E. None of the above 9. A car accelerates uniformly from rest to 36kmh−1 in 4 s. Calculate the magnitude of the acceleration and the distance covered during this 4s interval. A. 2.5ms−2 , 20m B. 1.5ms−2 , 10m C. 1.0ms−2 , 5m D. 0.5ms−2 , 2.5m E. 0.25ms−2 , 2.5m 10. A car accelerates uniformly from rest at 4ms−2. How far will it travel in the fifth complete second. 11. A car moves with a speed of 30ms−1. Calculate the distance travelled in 30s. 12. An orange fruit drops to the ground from the top of a tree 45m tall. How long does it take to reach the ground. 13. A particle starts from rest and moves with a constant acceleration of 0.5ms−2. Calculate the time taken by the particle to cover a distance of 25m 14. A fruit drops from a tree 20m tall. The time it takes to get to the ground is (A) 5.0s (B) 4.0s (C) 2.5s (D) 2.0s 15. A ball is dropped from a height of 45m above the ground. Calculate the velocity of the ball just before it strikes the ground 16. A car takes off from rest and covers a distance of 80m on a straight road in 10s. Calculate the magnitude of its acceleration. 17. A body accelerates from rest at 2ms−2. Calculate its velocity after travelling 9m. 18. A car moving with a speed of 90 km/hr was brought to rest by the application of the brakes in 10s. How far did the car travel after the brakes were applied. 19. A ball is dropped from a height of 45m above the ground. Calculate the velocity of the ball just before it strikes the ground 20. A ball is thrown vertically upwards from the ground with an initial velocity of 500m/s. What is the total time spent by the ball in the air. 21. A stone is projected vertically upward with a velocity of 20ms−1. Two seconds later a second stone is similarly projected with the same velocity. When the two stones meet, the second one is rising at a velocity of 10ms−1. Neglecting air resistance, calculate the (i) length of time the second stone is in motion before they meet (ii) velocity of the first stone when they meet 22. A stone is released from a height of 80m above the ground. Calculate its velocity just before it strikes the ground 23. A small metal ball is thrown vertically upwards from the top of a tower with an initial velocity of 20ms−1. If the ball took a total of 6 seconds to reach the ground level, determine the height of the tower. 24. A tennis ball is dropped onto the floor from a height of 4.0m. It rebounds to a height of 3.0m. If the ball was in contact with the floor for 0.010 s, calculate its average acceleration during contact. 25. A ball is thrown upward with speed 12m/s from the top of a building. How much later must a second ball be dropped from the same starting point if it is to hit the ground at the same time as the first ball. The initial position is 24m above the ground (A) 2.54s (B) 1.54s (C) 3.54s (D) 4.33s 26. A train moving between two stations 1100m apart accelerates uniformly from rest for 40 s, and then moves at constant speed until the brakes are applied resulting in a constant deceleration. If it comes to rest after 30 s and the whole journey takes 90 s, find the maximum speed, the acceleration, and the retardation. 27. A moving car passes three points A, B and C which are 150m apart. The time taken to move from A to B was 10 s, and the time taken to move from B to C was 5 s. If the motion of the car was uniformly accelerated, how fast was the car moving as it passed points A, B and C? 28. A stone is projected vertically upward with a speed of 14ms1 from a tower 100m high. Find the maximum height attained and the speed with which it strikes the ground. 29. A car driver travelling at 72kmh1 suddenly sees a fallen tree on the road 40m ahead. He puts on the brakes to stop before he hits the tree. To put on the brakes requires 0.75 s (the reaction time of the driver), after which the retardation is 8ms2. What is the total stopping time? How far does he travel before the brakes are applied? What is his total stopping distance? If he subsequently travels at twice the speed, how far ahead should he be able to see clearly for safety? (Assume the deceleration is the same.) 30. A stone is dropped and then 1.0 s later, from a point 5.0m lower, a second stone is dropped. When will the two stones be 15m apart? 31. Four-tenths of a second after bouncing on a trampoline, a gymnast is moving upward with a speed of 6.0ms1. To what height above the trampoline does the gymnast rise before falling back down? 32. Two trucks A and B, each traveling at 40 km/hr, move towards each other. At the instance when the two trucks are at a distance 50km from one another, a car moving at 60 km/hr overtakes A. How far behind the car is A at the point when the car meets B 33. A motorist travelling 31m/s passes a stationary motorcycle police officer 2.5s after the motorist passes, the police officer starts to move and accelerates in pursuit of the speeding motorist. The motorcycle has constant acceleration of 3.6m/s2. How fast will the police officer be travelling when he overtakes the car (A) 33m/s (B) 53m/s (C) 83m/s (D) 43m/s VELOCITY-TIME GRAPH 1. Which of the following is true for a Velocity-Time graph? A. The slope at a particular time gives the magnitude of the instantaneous acceleration at the time B. If the graph is a straight line, then the acceleration is uniform else non-uniform C. The area under the graph is the distance covered D. All of the above E. None of the above 2. Two points on a velocity time graph have coordinates (5s, 10ms−1 ) and (20s, 20ms−1 ). Calculate the mean acceleration between the two points. 3. What is the acceleration between two points on a velocity-time graph which has coordinates (10s, 15ms−1 ) and (20s, 35ms−1 ) 4. A driver traveling at 160km/hr applies his brakes for 6s. Calculate the velocity of the car at the end of the period, if the car decelerates at 4.00ms−2 5. A car starts from rest, accelerating at 6ms−2 for 5s. It continues at this speed for 25s, and then comes to a stop in 4s. Calculate (a) the total distance covered, and (b) the average velocity for the whole displacement. 6. A car starts from rest and attains a velocity of 90 km/hr after covering a distance of 75m. Calculate the time taken by the car to reach this speed. 7. A car starts from rest at a check point A and comes to rest at the next check point B, 6km away, in 3 minutes. It has first, a uniform acceleration for 40s, then a constant speed and is brought to rest with a uniform retardation after 20s. Sketch a velocity-time graph of the motion. Determine (i) the maximum speed (ii) the retardation 8. A body at rest is given an initial uniform acceleration of 8.0ms−2 for 30s after which the acceleration is reduced to 5.0ms−2 for the next 20s. The body maintains the speed attained for 60s after which it is brought to rest in 20s. (a) Draw the velocity-time graph of the motion using the information given above (b) Using the graph, calculate the (i) maximum speed attained during the motion (ii) average retardation as the body is being brought to rest (iii) total distance travelled during the first 50s (iv) average speed during the same interval as in (iii) 9. A body at rest is given an initial acceleration of 6.0ms−2 for 20s after which the acceleration is reduced to 4.0ms−2 for the next 10s. The body maintains the speed attained for 30s. Draw the velocity-time graph of the motion using the information given above. From the graph, calculate (i) maximum speed attained during the motion (ii) total distance travelled during the first 30s (iii) average speed during the same time interval as in (ii) above 10. The engine of a car which started from rest and which moved with an acceleration of 2ms−2 was turned off after 3 s. the car accelerated for 10 s at 25ms−2 before brakes are applied after which comes to rest in 3 s later. Calculate the total distance through which the car moved. A. 80.75 m B. 61.75 m C. 50.75 m D. 30.75 m E. 20.75 m 11. A car starts from rest and accelerates uniformly for 5s until it attains a velocity of 30ms−1. It then travels with uniform velocity for 15s before decelerating uniformly to rest in 10s (a) sketch a graph of the motion (b) using the graph above, calculate the (i) acceleration during the first 5s (ii) deceleration during the last 10s (iii) total distance covered throughout the motion.  PROJECTILES 1. An object is projected with velocity of 80m/s at an angle of 30o to the horizontal. Find the maximum height reached. 2. A particle is projected with a velocity of 25m/s. What is the maximum range for the particle 3. A long-jumper had a take-off velocity of 9.5m/s. What is the maximum possible horizontal distance the man can jump 4. A particle is projected into the air at a speed of 25ms−1 at an angle 40o above the horizontal (a) How long does it take the particle to reach its maximum height (b) What is its horizontal distance covered. 5. A particle is launched such that its maximum range is 26.4m. What iis the speed at which it is launched 6. A particle projected at angle θ above the horizontal has a velocity v̄ = (15.5i + 4.8j)ms−1 at time t=0.8s after launching (a) What is the maximum height by the particle (b) What is the range of the particle 7. A ball is kicked into the air. When it reaches the vertical height of 7.5m the velocity is measured to have a horizontal component 10.4ms−1 and vertical component 3.7ms−1. Calculate the maximum height and horizontal distance which the ball travels. 8. A projectile is projected into the air at 36ms−1. If it travels a horizontal distance of 99.3m (a) at what angle above the horizontal is it projected (b) what is the maximum vertical height it climbed 9. An object is projected with velocity of 100ms−1 from the ground level at an angle of θ to the vertical. If the total time of flight of the projectile is 10s, calculate θ 10. A ball is projected horizontally from the top of a hill with a velocity of 20ms−1. If it reaches the ground 4s later. What is the height of the hill 11. An object is projected with a velocity of 100ms−1 at an angle of 60o to the vertical. Calculate the time taken by the object to reach the highest point 12. A body is projected with an initial velocity 80m/s and 30o to the horizontal ground. Calculate (a) the maximum height it will attain (b) the height attained at instant t = 5s (c) the velocity at time t = 1.5s (d) the distance through an inclination from origin at t = 6s (e) the time spent to reach a height 10m above horizontal ground. 13. A stone thrown horizontally from the top of a vertical wall with a velocity of 15m/s, hits the horizontal ground at a point 45m from the base of the wall. Calculate the height of the wall? 14. A stone is projected horizontally with a velocity of 10m/s from the top of a cliff of height 45m. Calculate the horizontal distance covered by the stone from the foot of the cliff 15. A particle is projected horizontally at 10m/s from a height of 45m. Calculate the horizontal distance covered by the particle before hitting the ground. 16. A stone projected horizontally from the top of a tower with a speed of 4ms−1 lands on the level ground at a horizontal distance 25m from the foot of the tower. Calculate the height of the tower. 17. A particle is projected horizontally at 15ms−1 from a height of 20m. Calculate the horizontal distance covered by the particle just before hitting the ground. 18. A ball rolls off the edge of a tabletop 1m above the floor, and strikes the floor at a point 1.5m horizontally from the edge of the table. (a) Find the time of flight. (b) Find the initial velocity. (c) Find the magnitude and direction of the velocity of the ball just before it strikes the floor. 19. A football is kicked with an initial speed of 22ms1 at an angle θ above level ground. The ball reaches a maximum height H; and its range is R (maximum horizontal distance). (a) Calculate the values of H and R for (i) θ = 20o ; (ii) θ = 45o ; (iii) θ = 70o. (b) Sketch these three trajectories roughly to scale. (c) Use your sketch and a sensible guess to answer the following question: For what value of θ is R a maximum? 20. A man stands on the roof of a building and throws a ball upwards with a velocity of magnitude 60ms1 at and angle of 33.0o above the horizontal. The ball leaves his hand at a point 30m above the ground. Calculate (a) the maximum height above the roof reached by the ball; (b) the magnitude of the velocity of the ball just before it strikes the ground; (c) the horizontal distance from the base of the building to the point where the ball strikes the ground. 21. An object is projected downward at an angle of 30o to the horizontal, with an initial speed of 40ms1 , from the top of a tower 150m high. What will be the vertical component of its velocity when it strikes the ground? In what time will it strike the ground? How far from the tower will it strike the ground? At what angle with the horizontal will it strike? 22. Before leaving the ground, an aircraft moves with constant acceleration and travels 720m in 12s from rest. It then leaves the ground. Determine (a) the acceleration, (b) the speed with which it leaves the ground, (c) the distance covered during the first second and during the twelfth second. 23. An archer standing on a cliff 48m above the level field below shoots an arrow at an angle of 30o above horizontal with a speed of 80ms−1. How far from the base of the cliff will the arrow land (A) 482m (B) 682m (C) 582m (D) 982m Each question attracts #500. Come to the tutorial today from 12pm, solve any question correctly and get #500 @ Benson hall, opp. MBA, faculty of science. JOIN BUNDAY TUTORIAL TODAY...if you are not a bundite, you are wrong