# NCERT Solutions for Class 7 Science Chapter 13: Motion and Time The chapter starts with the discussions of the motion of the body. The difference between speed and velocity, the motion of a pendulum, and our everyday life experiences have been elaborated upon in this chapter. The following are the points discussed in the chapter:

• The distance moved by an object in a unit time is called its speed. It is a scalar quantity.
• The distance moved by an object in a unit time in a specific direction is called its velocity. It is a vector quantity.
• The speed of an object is the distance travelled divided by the time taken to cover that distance. Its basic unit is metre per second (m/s).
• Odometer is used to measure the distance moved by the vehicle.
• Periodic events are used for the measurement of time. The periodic motion of a pendulum has been used to make clocks and watches.
• The motion of objects can be presented in pictorial form by their distance-time graphs. The distance-time graph for the motion of an object moving with a constant speed in a straight line.