1. What is rest and motion?

Rest is a state where an object's position does not change with respect to a reference point, while motion is when its position changes continuously.

2. What is the difference between scalar and vector quantity?

Scalar quantity is a physical quantity that has only magnitude while vector quantity requires both magnitude and direction.

Scalar quantity: Mass, temperature, Distance, energy, speed etc. 

Vector quantity: Force, velocity, acceleration, momentum etc.

3. What is displacement, Can displacement be zero?

Displacement is the shortest distance travelled by an object in a specific direction, from its initial to its final position. Yes, displacement can be zero when the initial and final positions are the same.

4. What is the difference between distance and displacement?

Distance is the actual path travelled by an object while displacement is the shortest distance travelled by an object in a specific direction.

6. What is the difference between uniform and non-uniform motion?

Uniform motion is when an object travels equal distances in equal intervals of time, i.e. Velocity is constant. Non-uniform motion is when an object travels unequal distances in equal intervals of time, i.e. Velocity is not constant.

7. What is the difference between accelerated and de-accelerated motion?

Accelerated motion is when the velocity of an object increases with time while de-accelerated motion is when the velocity of an object decreases with time.

8. What is speed and its SI unit ?

Speed is the measurement of the distance travelled by an object per unit time. And the SI unit of speed is m/s (meters/second).

9. What is the average speed?

The average speed is the total distance travelled by an object divided by the total time taken.

10. How can we convert km/hr to m/s and what will be the speed of the body in m/s and km/hr if it travels 40 kms in 5 hrs?

To convert km/hr to m/s, multiply the value by 5/18.

Distance(s) = 40 km

Time(t)  = 5 hrs.

Speed(in km/hr) = Total distance/Total time = 40/5 = 8 km/hr

Speed (in m/s) = (8 × 5/18)= 40/18 = 2.22 m/s

11. What is velocity?

Velocity is a vector quantity that describes the rate at which an object changes its position. It is defined as the displacement of an object per unit time and includes both magnitude (speed) and direction. The SI unit for velocity is meters per second (m/s).

12. What is acceleration?

Acceleration is the rate of change of velocity with time, given by the formula a = (v-u)/t, where v is the final velocity, u is the initial velocity, and t is the time taken.

13. What is deceleration?

Deceleration is the opposite of acceleration and is seen in non-uniform motion during a decrease in velocity with time. Its formula is the same as acceleration, a' = (v-u)/t, but the velocity is decreasing here.

14. A car starts from rest and reaches a velocity of 20 m/s in 5 seconds. Calculate its acceleration.

Initial velocity (u) = 0 m/s

Final velocity (v) = 20 m/s

Time (t) = 5 s

Acceleration (a) = ?

We know that, a = (v-u)/t

a = (20-0)/5

a = 4 m/s²

Therefore, the acceleration of the car is 4 m/s².

15. What is a distance-time graph?

A distance-time graph (s/t graph) is a graph that shows the distance traveled by an object on the y-axis and the time taken on the x-axis.

16. What does the area under a velocity-time graph represent?

The area under a velocity-time graph represents the distance traveled by an object.

17. What is the first equation of motion?

The first equation of motion is v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time taken. This equation can be used to calculate the final velocity of an object when we know the initial velocity, acceleration, and time.

18. What is the second equation of motion?

The second equation of motion is s = ut + 1/2 at², where s is the distance traveled, u is the initial velocity, a is the acceleration, and t is the time taken. This equation can be used to calculate the distance traveled by an object when we know the initial velocity, acceleration, and time.

19. What is the third equation of motion?

The third equation of motion is v² = u² + 2as, where v is the final velocity, u is the initial velocity, a is the acceleration, and s is the distance traveled. This equation can be used to calculate the final velocity of an object when we know the initial velocity, acceleration, and distance traveled.

20. What is uniformly accelerated motion?

Uniformly accelerated motion is when an object moves with a constant acceleration, i.e., there is an equal increase in velocity in equal intervals of time throughout the motion of the object.