- Av = u + at
- Bs = ut + 0.5at²
- Cv² - u² = 2as
- DAll of the above
The equation v² - u² = 2as directly relates initial velocity (u), final velocity (v=0 for stopping), acceleration (a, negative for braking), and distance (s). It shows that 's' is proportional to u², hence higher initial speed means significantly longer braking distance.
More Questions on Describing Motion Around Us
1Give an example of a situation where an object travels a considerable distance but its displacement is zero.
→ 2Why do objects thrown upwards eventually fall back down? Relate this to acceleration.
→ 3How would a distance-time graph differ from a velocity-time graph for an object moving with uniform speed in a straight line?
→ 4A body moves 6m towards East and then 8m towards North. If it takes 2 seconds for this motion, calculate its average velocity.
→ 5What is the nature of the velocity and acceleration in uniform circular motion?
→ 6Assertion (A): An object can have varying speed but constant velocity. Reason (R): Velocity depends on both speed and direction, so if speed varies, velocity must also vary.
→ 7A motorboat starting from rest on a lake accelerates in a straight line at a constant rate of 3.0 m/s² for 8.0 s. How far does the boat travel during this time?
→ 8Draw a rough distance-time graph for a car accelerating from rest.
→ 9Why is acceleration considered a vector quantity?
→ 10A stone is thrown upwards with an initial velocity of 40 m/s. Taking g = 10 m/s², what is the maximum height reached by the stone?
→ 11If two trains are moving in the same direction with the same speed, what is the relative velocity of one train with respect to the other?
→ 12A body's velocity changes from 10 m/s to 40 m/s in 5 seconds. What is its average acceleration?
→ 13An object moves in a straight line. Its velocity-time graph first shows a positive constant velocity, then drops to zero, and then shows a negative constant velocity of the same magnitude. Describe the object's motion.
→ 14Assertion (A): The speedometer of a car measures its instantaneous speed. Reason (R): Speedometer measures the distance covered per unit time.
→ 15What is the difference between instantaneous velocity and average velocity in uniform circular motion?
→ 16A free-falling object covers a distance of 45 m in the last second of its fall. If it started from rest, what is the total height from which it fell? (Take g = 10 m/s²)
→ 17What does a straight line with a negative slope in a velocity-time graph represent?
→ 18Give two examples of motion where the acceleration of the object is zero.
→ 19A bus starts from rest with an acceleration of 2 m/s² for 10 seconds. Then it moves with a constant velocity for 10 seconds. Finally, it decelerates at 4 m/s² to come to rest. Calculate the total distance covered.
→ 20When you are sitting in a moving train, why do trees outside appear to be moving backwards?
→ 21An object traveling at 30 m/s starts to decelerate at a rate of 3 m/s². How much time will it take to come to a complete stop?
→ 22Can the direction of acceleration be opposite to the direction of velocity? Provide an example.
→ 23A velocity-time graph for a car shows a rectangle with height 15 m/s and width 10 s. What is the displacement of the car?
→ 24Why are safety belts crucial in vehicles, especially during sudden stops or collisions? Relate this to a concept of motion.
→ 25How would a velocity-time graph look for an object undergoing increasing acceleration?
→ 26Distinguish between uniform and non-uniform motion with respect to speed and distance.
→ 27A car travels the first half of a journey at an average speed of 40 km/h and the second half at an average speed of 60 km/h. What is the average speed for the entire journey?
→ 28Assertion (A): An object undergoing free fall experiences uniform acceleration. Reason (R): The force of gravity acting on an object during free fall is constant (neglecting air resistance).
→ 29How does a distance-time graph for non-uniform speed appear?
→ 30Explain why a body moving with uniform speed in a circular path is said to be undergoing accelerated motion.
→ 31A car accelerates uniformly from 10 m/s to 20 m/s in 5 seconds. What distance does it cover in this time?
→ 32A stone is thrown vertically upwards and reaches a maximum height. What is its instantaneous velocity at the highest point?
→ 33If the slope of a distance-time graph is decreasing, what does it signify about the motion of the object?
→ 34Which pair of quantities consists of one scalar and one vector quantity?
→ 35A car moving at 20 m/s applies brakes and comes to rest in 10 seconds. Calculate the deceleration (retardation) of the car.
→ 36What does the area under a velocity-time graph represent?
→ 37Identify a scenario where an object experiences non-uniform velocity but uniform acceleration.
→ 38What is the significance of the slope of a velocity-time graph?
→ 39A train starting from rest accelerates uniformly and attains a speed of 36 km/h in 5 minutes. Calculate the distance traveled by the train during this period.
→ 40A car travels from point A to point B, then turns around and travels halfway back to point A. Compare the total distance covered and the magnitude of its displacement.
→ 41A velocity-time graph shows a horizontal line above the time axis. What does this indicate about the object's motion?
→ 42Assertion (A): An object can have zero velocity but non-zero acceleration. Reason (R): When an object is thrown vertically upwards, at its highest point, its velocity is zero but acceleration due to gravity is still acting on it.
→ 43An athlete runs along a circular track with a constant speed. Is the athlete's motion an example of accelerated motion? Justify your answer.
→ 44A stone is dropped from a height. If its velocity after 2 seconds is 19.6 m/s, what is the acceleration due to gravity? (Assume initial velocity is 0 m/s).
→ 45Under what condition can the magnitude of displacement be equal to the total distance covered by an object?
→ 46The distance-time graph for an object is a straight line passing through the origin. What can be inferred about the object's motion?
→ 47A bicycle starting from rest accelerates uniformly to a velocity of 18 km/h in 5 seconds. Calculate its acceleration in m/s².
→ 48A car travels at a constant speed of 60 km/h in a straight line. Which of the following statements about its motion is INCORRECT?
→ 49A person walks 10 m East, then 5 m North, and finally 10 m West. What is the magnitude of their displacement from the starting point?
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