Advertisements
Advertisements
प्रश्न
State and explain the law of inertia (or Newton's first law of motion).
Advertisements
उत्तर
Statement of Newton's first law: If a body is in a state of rest, it will remain in the state of rest, and if the body is in the state of motion, it will remain moving in the same direction with the same speed unless an external force is applied on it.
Explanation: Newton's first law can be explained in the following two parts:
(i) Definition of inertia: The 1st part of Newton's first law of motion gives the definition of inertia, according to which an object cannot change its state by itself.
Example: A book lying on a table will remain in its position unless it is displaced.
(ii) Definition of force: The 2nd part of Newton's first law defines force, according to which force is that external cause which can move a stationary object or which can stop a moving object.
Example: A book lying on a table is displaced from its place when it is pushed.
APPEARS IN
संबंधित प्रश्न
Name the scientist who gave the laws of motion.
Fill in the following blank with suitable word :
Newton’s first law of motion is also called Galileo’s law of ………………………
The figure shows a light spring balance connected to two blocks of mass 20 kg each. The graduations in the balance measure the tension in the spring. (a) What is the reading of the balance? (b) Will the reading change if the balance is heavy, say 2.0 kg? (c) What will happen if the spring is light but the blocks have unequal masses?
Match the following
| Column I | Column II |
| Newton’s I law | propulsion of a rocket |
| Newton’s II law | Stable equilibrium of a body |
| Newton’s III law | Law of force |
| Law of conservation of linear momentum | Flying nature of bird |
If a 5 N and a 15 N forces are acting opposite to one another. Find the resultant force and the direction of action of the resultant force.
A body of mass 10 kg is acted upon by two perpendicular forces, 6 N and 8 N. The resultant acceleration of the body is ______.
- 1 m s–2 at an angle of tan−1 `(4/3)` w.r.t 6 N force.
- 0.2 m s–2 at an angle of tan−1 `(4/3)` w.r.t 6 N force.
- 1 m s–2 at an angle of tan−1 `(3/4)` w.r.t 8 N force.
- 0.2 m s–2 at an angle of tan−1 `(3/4)` w.r.t 8 N force.
A force F is applied to the initially stationary cart. The variation of force with time is shown in the figure. The speed of the cart at t = 5 sec is ______.
How is force defined according to Newton’s First Law?
When does an object accelerate?
An insect is at the bottom of a hemispherical ditch of radius 1 m. It crawls up the ditch but starts slipping after it is at height h from the bottom. If the coefficient of friction between the ground and the insect is 0.75, then h is ______. (g = 10 ms−2)
