Which of the following are not correct?
(a) The basic unit of time is second.
(b) Every object moves with a constant speed.
(c) Distances between two cities are measured in kilometres.
(d) The time period of a given pendulum is not constant.
(e) The speed of a train is expressed in m/h.

3

(a)

A simple pendulum takes 32 s to complete 20 oscillations. What is the time period of the pendulum?

3

(a)

The distance between two stations is 240 km. A train takes 4 h to cover this distance. Calculate the speed of the train.

3

(a)

Salma takes 15 min from her house to reach her school on a bicycle. If the bicycle has a speed of 2 m/s, calculate the distance between her house and the school.

3

(a)

Suppose, the two photographs, shown in two figures had been taken at an interval of 10 s. If a distance of 100 m is shown by 1 cm in these photographs, then calculate the speed of the circled car.

3

(a)

Differentiate between a uniform and non-uniform motion.

3

(a)

Briefly mention how many types of motion are there. Also, name all of them.

3

(a)

The average age of children of class VII is 12 years and 3 months. Express this age in second.

3

(a)

Starting from A, Paheli moves along a rectangular path ABCD as shown in figure. She takes 2 min to travel each side. Plot a distance-time graph and explain whether the motion is uniform or non-uniform.

3

(a)

The following figure shows the distance-time graph for the motion of two objects 0 and E. Which one of them is moving slower?

3

(a)

The following figure shows the distance-time graph for the motion of two vehicles (C and D). At what time and distance (from the starting point), they will cross each other.

3

(a)

In a match, a team scored 200 runs, out of which they made twelve fours, three sixes, twenty times three runs, twenty times two runs and thirty four times one run. Show this by a pie chart. (Approx

3

(a)

In a cricket match a team scored 3, 4, 2, 10, 8, 6 runs in first 6 overs. Show these runs by a bar graph (supply graph paper).

3

(a)

What were the definitions of a day, a month and a year for our ancestors ?

3

(a)

What is a pendulum ? How can it be used to determine time?

3

(a)