Question

Question 62:
Study the speed-time graph of a car given alongside and answer the following questions:

(i) What type of motion is represented by OA ?
(ii) What type of motion is represented by AB ?
(iii) What type of motion is represented by BC ?
(iv) What is the acceleration of car from O to A ?
(v)What is the acceleration of car from A to B ?
(vi) What is the retardation of car from B to C ?

Lakhmir Singh Physics Class 9

Answer 1

Explanation:

1. The motion from O to A represents a Uniform acceleration. The constant rate of acceleration is derived from the constant increase in speed at a particular time.
2. The motion from A to B has a Constant speed. This is because speed remains constant $6 \frac{m}{s}$ for the time.
3. Uniform retardation is represented by BC. This is because there’s a steady rate of decrease in speed per unit time. The acceleration of a car is $\frac{\frac{6}{4 m}}{s^{2}}=\frac{2.5 m}{s^{2}}$.
4. The acceleration of the car from point A to B is Zero. This is because there’s no change in velocity at this moment.
5. The retardation of the car from point B to C is $=\frac{\frac{6}{6 m}}{s^{2}}=\frac{1 . m}{s^{2}}$