1 The speed of an object is determined by comparing the distances moved by them in a unit time.
Answer: True
Explanation: The distances moved by objects in a unit time helps determine their speeds.
2 Uniform motion refers to an object moving with a constant speed along a straight line.
Answer: True
Explanation: An object moving with a constant speed along a straight line is in uniform motion.
3 The average speed of an object is calculated by dividing the total distance covered by the total time taken.
Answer: True
Explanation: The average speed is determined by dividing the total distance covered by the total time taken.
5 Speed is the distance covered by an object in a unit time.
Answer: True
Explanation: THe distance covered by an object in a unit time.
6 If the speed of an object keeps changing, its motion is said to be uniform.
Answer: False
Explanation: If the speed of an object keeps changing, its motion is said to be non-uniform.
7 The faster vehicle in a race is determined by the one that covers the shortest time to travel a given distance.
Answer: False
Explanation: The faster vehicle in a race is determined by the one that takes the shortest time to cover a given distance.
8 The speed of an object can be determined by comparing the time taken by it to cover a certain distance.
Answer: True
Explanation: Once we can measure the time taken by an object to cover a certain distance, we can determine its speed.
9 Clocks and watches measure time using linear motion.
Answer: False
Explanation: Clocks and watches make use of periodic or oscillatory motion, not linear motion.
10 The time period of a pendulum is the time taken for 10 oscillations.
Answer: False
Explanation: The time period of a pendulum is the time taken for one oscillation, not 10 oscillations.
11 The time period of a pendulum can be measured by counting the number of oscillations.
Answer: True
Explanation: The time period of a pendulum can be measured by counting the number of oscillations.
12 The basic unit of time is a minute (min).
Answer: False
Explanation: The basic unit of time is a second (s), not a minute.
13 The basic unit of speed is expressed as meters per minute (m/min).
Answer: False
Explanation: The basic unit of speed is expressed as meters per second (m/s), not meters per minute.
14 There are 3600 seconds in a day.
Answer: True
Explanation: A day consists of 24 hours, and each hour has 60 minutes, and each minute has 60 seconds. So, there are 24 x 60 x 60 = 3600 seconds in a day.
15 Galileo Galilei noticed that a pendulum of a given length takes different times to complete one oscillation.
Answer: False
Explanation: Galileo Galilei noticed that a pendulum of a given length always takes the same time to complete one oscillation.
16 Quartz clocks are less accurate than the clocks used before pendulum clocks.
Answer: False
Explanation: Quartz clocks are more accurate than the clocks used before pendulum clocks.
17 Different designs of time measuring devices were developed only in specific regions of the world.
Answer: False
Explanation: Different designs of time measuring devices were developed in different parts of the world, not limited to specific regions.
19 Speed is calculated by dividing distance by time.
Answer: True
Explanation: Speed is calculated by dividing the distance traveled by the time taken.
20 The speed of an object is measured in meters per second.
Answer: True
Explanation: The basic unit of speed is meter per second (m/s).
21 A speedometer measures the distance traveled by a vehicle.
Answer: False
Explanation: A speedometer measures the speed of a vehicle, not the distance traveled.
22 The distance-time graph for an object moving with a constant speed is a curved line.
Answer: False
Explanation: The distance-time graph for an object moving with a constant speed is a straight line.
23 In a distance-time graph, the slope represents the object’s speed.
Answer: True
Explanation: The slope of a distance-time graph indicates the speed of the object. A steeper slope represents a higher speed.
24 The choice of scales in a graph is not important and does not affect the accuracy of the representation.
Answer: False
Explanation: The importance of choosing suitable scales to accurately represent the data on a graph.
25 If the distance-time graph is a straight line, it indicates that the object’s speed is changing.
Answer: False
Explanation: A straight line on a distance-time graph represents an object moving with a constant speed. If the line is curved, it indicates a change in speed.
26 A distance-time graph can provide information about the distance moved by an object at any instant of time.
Answer: True
Explanation: The passage states that a distance-time graph allows us to determine the distance moved by an object at any specific time.
27 The distance covered by a bus at a specific time can be found by drawing a perpendicular line from the time on the y-axis.
Answer: False
Explanation: To find the distance covered by a bus at a specific time, a perpendicular line is drawn from the time on the x-axis, not the y-axis.
28 If the distance-time graph is a curved line, it indicates that the object is moving in a circular path.
Answer: False
Explanation: Anything about the shape of the distance-time graph indicating circular motion. It only suggests that a curved line represents changing speed.