DoE GNCT of Delhi Class 9 Worksheet 39 Science Solution

Directorate of GNCT of Delhi Class 9 Worksheet 39 Subject: Science 

DoE GNCT of Delhi Class 9 Worksheet 39 Science Solution

Class 9 Worksheet 39 Science Question and Answer:

Q1. Define Inertia

Ans: The natural tendency of an object to resist a change in their state of uniform motion or of rest is called inertia. Every object opposes the changes in its state of motion or rest.

Q2. Write first law of motion with example.

Ans: Laws of motion including first law are given by Newton. According to first law of motion "An object remains in a state of rest or of uniform motion in straight line unless acted upon by an unbalanced force". This law is also called as law of inertia. 

Example: we feel jerk in forward direction when breaks are applied suddenly on the moving bus or car.

Q.3 In which direction the passengers will feel jerk, if the bus starts moving suddenly? Explain

Ans: Backward direction 

When a bus at rest starts, to move suddenly, the passengers sitting in it jerk in backward direction due to their inertia of rest.

Q.4 Which will have more inertia:

a) a car and a bus

Ans: A bus

b) a bicycle and a motorcycle

Ans: A Motorcycle 

c) a cart and a train 

Ans: A Train

Note: As per law of inertia heavier object will have larger inertia in comparison to the lighter object.

Also Read: Worksheet 39 Hindi Solution

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