Std 7 Science 1 Chapter 7 : Motion, Force and Work

Title : Std 7 Science 1 Chapter 7 : Motion, Force and Work

Distance and displacement II. Speed and velocity III. Average velocity and instantaneous velocity IV. Acceleration V. Force and acceleration VI. Newton’s First Law of Motion VII. Force, displacement and work

Maharashtra state board solutions for class 7 SSC board science part STD 7- General science  Motion, Force and Work

 Know everything about Motion  force and work. Maharashtra state board SSC .Get detailed Questions and answers for chapter 7 General Science Distance and displacement II. Speed and velocity III. Average velocity and instantaneous velocity IV. Acceleration V. Force and acceleration VI. Newton’s First Law of Motion VII. Force, displacement and work

Important question and answers

What is meant by speed?

 Answer: Speed is the distance traveled per unit of time. *

Q.2) What is the formula for calculating speed?

Answer: The formula for calculating speed = Distance /time.

Q.4) What is meant by motion?

Answer: Motion is the change in position of an object with respect to its surroundings in a given interval of time.

*Q.5) What causes a change in motion?

Answer: When a force is applied on an object at rest it is put in motion and when force is applied on an object in motion it will cause change in motion.

**Q.6) Define distance.

 Answer: The length of the route actually traversed by a moving body, irrespective of the direction, is called distance. Distance is a scalar quantity

**Q.7) What is displacement?

Answer: The minimum distance traversed by a moving body in one direction from the original point to reach the final point, is called displacement

Acceleration

*Q.1) What is the cause of acceleration?

 Answer: Newton's second law says that when a constant force acts on a massive body, it causes it to accelerate, i.e., to change its velocity, at a constant rate. In the simplest case, a force applied to an object at rest causes it to accelerate in the direction of the force.

**Q.2) What is acceleration?

 Answer: Acceleration is the rate of change of velocity of an object with respect to time. Acceleration = Change in velocity / Time taken for change

State Newton’s first law of motion.

 Answer: If no force 1s acting on a body, its velocity does not change, i.e. the body does not accelerate. In other words, if a body is stationary, it will remain stationary. If it is in motion, it will continue moving with the same velocity and in the same direction.

**Q.4) Express 1 Newton.

 Answer: If you place the 1kilogram standard weight on a surface with no friction and pull it with an acceleration of 1m/s2 , the force applied is called 1N (1 Newton).

Force, displacement and work

**Q.1) Express the relationship between work and force.

 Answer: The following formula expresses this relationship: Work (W) done by the force = force (F) applied to the body X displacement (s) of the body that takes place in the direction of the force, W = F X s

**Q.2) What is the unit of work, force and displacement?

Answer: In the SI system, the unit of work is Joule (J), while the unit of force is Newton (N) and the unit of displacement is metre (m). In the CGS system the unit of work is erg.