1 The most convenient way to find out which of the two or more objects is moving faster is to compare the distances moved by them in a unit _______.
Answer: time
Explanation: The sentence suggests that comparing the distances moved by objects in a unit of time helps determine their relative speeds.
2 When we say that a car is moving with a speed of 50 kilometres per hour, it implies that it will cover a distance of 50 kilometers in _______ hour.
Answer: one
Explanation: The sentence indicates that when a car has a speed of 50 kilometers per hour, it means it will cover a distance of 50 kilometers in one hour.
3 The speed calculated here is actually the ________ speed of the car.
Answer: average
Explanation: The sentence clarifies that the speed calculated refers to the average speed of the car.
4 If the speed of an object moving along a straight line keeps changing, its motion is said to be ________.
Answer: non-uniform
Explanation: The sentence states that when the speed of an object moving along a straight line keeps changing, its motion is considered to be non-uniform.
5 The distance covered by an object in a unit time is defined as the ________ of the object.
Answer: speed
Explanation: The sentence defines the distance covered by an object in a unit time as its speed.
6 In everyday life, we seldom find objects moving with a ________ speed over long distances or for long durations of time.
Answer: constant
Explanation: The sentence mentions that objects seldom move with a constant speed over long distances or for long durations of time in everyday life.
7 We can determine the speed of a given object once we can measure the ________ taken by it to cover a certain distance.
Answer: time
Explanation: The sentence explains that measuring the time taken by an object to cover a certain distance helps determine its speed.
8 Clocks and watches make use of __________ motion to measure time.
Answer: periodic or oscillatory
Explanation: Clocks and watches make use of periodic or oscillatory motion to measure time.
9 A simple pendulum consists of a small metallic ball or a piece of stone suspended from a rigid stand by a __________.
Answer: thread
Explanation: A simple pendulum consists of a small metallic ball or a piece of stone suspended from a rigid stand by a thread.
10 The time taken by a pendulum to complete one oscillation is called its __________.
Answer: time period
Explanation: The time taken by a pendulum to complete one oscillation is called its time period.
11 To measure the time period of a pendulum, a __________ is required.
Answer: stopwatch
Explanation: A stopwatch is required to measure the time period of a pendulum.
12 The basic unit of time is __________.
Answer: second
Explanation: The basic unit of time is a second.
13 The time taken for 20 oscillations can be divided by 20 to get the time taken for __________ oscillation(s).
Answer: one
Explanation: By dividing the time taken for 20 oscillations by 20, you can obtain the time taken for one oscillation.
14 The time measured by quartz clocks is __________ accurate than that by the clocks available earlier.
Answer: more
Explanation: The time measured by quartz clocks is more accurate than that by the clocks available earlier.
15 The basic unit of speed is expressed as __________ per second.
Answer: meters
Explanation: The basic unit of speed is expressed as meters per second.
16 There are __________ seconds in a day.
Answer: 86,400
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 = 86,400 seconds in a day.
17 Galileo Galilei found that a pendulum of a given length takes __________ the same time to complete one oscillation.
Answer: always
Explanation: Galileo Galilei found that a pendulum of a given length always takes the same time to complete one oscillation.
18 In Class VI, you learned about three types of motions: motion along a __________ line, circular motion, and periodic motion.
Answer: straight
Explanation: The three types of motions learned in Class VI are motion along a straight line, circular motion, and periodic motion.
19 We can determine the speed of an object by comparing the distances moved by objects in a __________ time.
Answer: unit
Explanation: To determine the speed of an object, we compare the distances moved by objects in a unit time.
20 The speed of an object is calculated by dividing the total distance covered by the object by the __________ taken.
Answer: total time
Explanation:The speed of an object is determined by dividing the total distance covered by the object by the total time taken.
21 When an object’s speed keeps changing, its motion is said to be __________.
Answer: non-uniform
Explanation: When the speed of an object moving along a straight line keeps changing, its motion is considered non-uniform.
22 An object moving along a straight line with a constant speed is said to be in __________ motion.
Answer: uniform
Explanation: An object moving along a straight line with a constant speed is said to be in uniform motion.
23 The distance covered by an object in a unit time is referred to as the __________ of the object.
Answer: speed
Explanation: Speed as the distance covered by an object in a unit time.
24 The average speed of a car is calculated by dividing the __________ distance covered by the car by the total time taken.
Answer: total
Explanation: That the average speed of a car is determined by dividing the total distance covered by the car by the total time taken.
25 Speed is a measure of how fast an object is moving and is often expressed in units such as __________ per hour.
Answer: kilometers
Explanation: An example of speed being expressed in units such as kilometers per hour.
26 An object’s speed can be determined by comparing the distances moved by multiple objects in a __________ time.
Answer: unit
Explanation: The speed of an object can be determined by comparing the distances moved by multiple objects in a unit time.
27 The speed of an object indicates how quickly it covers a __________ distance in a given time.
Answer: certain
Explanation: The speed of an object indicates how quickly it covers a certain distance in a given time.