Science 2 Marks Questions

A car moving with a constant speed covers equal distance in equal intervals of time.

Such motion of car is represented in the given distance-time graph.

The distance-time graph of a car parked on a road side is such that with the increase in time, there is no change in distance, as shown in the given figure.

Straight line motion

The train is moving on a straight bridge. Therefore, it has a motion along a straight line.

Oscillatory motion

The hammer hits the electric bell and vibrates rapidly. Therefore, it is an oscillatory motion.

Oscillatory motion

The child on a see-saw goes up and down continuously. It oscillates up-down. Therefore, it is an oscillatory motion.

Circular motion

Merry-go-round has a circular motion. Therefore, a child sitting inside it will also have a circular motion

Straight line motion

The horse is pulling a cart on a straight road. Therefore, it has a motion along a straight line.

Oscillatory motion

While running, the hands move to and fro and repeat their motion after a given interval of time. Hence, it is an oscillatory motion.

In ancient time the time between one sunrise and the next was called a day. A month was measured from one new moon to the next and a year was fixed as the time taken by the earth to complete one revolution of the sun.

All clocks make use of some periodic motion.
The working principle of all clocks is same i.e. periodic motion.
A sundial measures the periodic position of shadow on a dial.
A pendulum clock measures number of oscillations of the bob.
A spring clock measures back and forth motion of the spring.
A quartz clock measures the number of vibrations or oscillations of the quartz crystal.

When a body travels equal distance in an equal interval of time, then the body is said to be in a uniform motion. When a body travels unequal distance in an equal interval of time, then the body is said to be in non-uniform motion.

Since, the speed i.e., the distance covered per unit time for the entire distance covered is not the same, therefore, the motion is a non-uniform motion.

The factors on which the time period of a simple pendulum depend are:

• Length of the pendulum.
• Acceleration due to gravity.

If a body covers equal distance in equal intervals of time, it is said to be in a uniform motion. For example, a car moving along a straight line. If a body covers unequal distance in equal intervals of time, it is said to be in non-uniform motion. For example, a racing horse.

We have observed that the position of stars and planets change while you remain stationary. In reality the earth is moving too. Thus, an object which appears to be at rest, may actually be in motion. Therefore, motion and rest are relative terms.

They do not have equal speed because they cover unequal distances in equal intervals of time. One of them has higher speed, whom has to cover larger distance with respect to other.

The distance covered by a moving object is the actual length of the path followed by the object is called. Distance is a scalar quantity. SI unit of distance is meter. But Displacement is the shortest distance covered by a moving object from the point of reference (initial position of the body), in a specified direction.

Distance time graphs gives information about the nature of the motion of an object like uniform or uniform motion. Motion of an object can be represented by its distance time graphs.

1. The wristwatch can be handled very easily to check the time in comparison to the wall clock.
2. The values showed by Chintoo’s mother here is the concern towards her four years old child and also the concern towards that wristwatch while considering the importance of money.

The interval between two events is called time. Example: The time between one sunrise and the next was called a day. Clocks or watches are the most common time measuring devices. The basic unit of time is a second. Its symbol is s. Larger units of time are minutes (min) and hours (h).

When you are driving a car, the car is said to be in motion because it is moving relative to the road but you are said to be at rest because you are at rest relative to the moving car.

Different types of motion are there and they can be named as follows:

• Periodic motion.
• Rolling motion.
• Rotatory motion.
• Oscillatory and vibratory motions.
• Translatory motion.

Different types of graphs are:

• Line graph.
• Pie chart.
• Bar graph.