Question

What do you mean by acceleration? Explain uniform and non-uniform acceleration by giving one example for each of them.

Answer 1

Acceleration:

1. It is the change of velocity of a body in one second.
2. Acceleration $\underset{a}{\to }$=$\frac{changeinvelocity}{time}$ .
3. It is a vector quantity.
4. SI unit of acceleration =$\frac{m}{s^2}$.

Uniform acceleration :

The acceleration of a body is said to be uniform if its velocity changes by equal amounts in equal intervals of time .

1. Consider a body moving along a straight line. Let its velocity at a point O be 10$\frac{m}{s}$, When the stopwatch is started.
2. The velocity of the body is found to be 12 $\frac{m}{s}$,14 $\frac{m}{s}$,16$\frac{m}{s}$ , and 18$\frac{m}{s}$.While at A, B, C, and D at times 1 s, 2 s, 3 s, and 4 s respectively.
3. It is clear that in each interval of 1 s the velocity changes by 2$\frac{m}{s}$. Such a body is said to possess uniform acceleration.
4. A body moving with uniform acceleration travels unequal distances in equal intervals of time.

Non-uniform velocity :

The acceleration of a body is said to be non-uniform if its velocity changes by unequal amounts in equal intervals of time.

1. Consider an example, let the velocity of the body as it reaches A, B, C and D be 12 $\frac{m}{s}$ ,15 $\frac{m}{s}$,19$\frac{m}{s}$ , and 24 $\frac{m}{s}$.
2. The change of velocity of the body in 1 second each is 2 $\frac{m}{s}$,3$\frac{m}{s}$,4$\frac{m}{s}$ and 5 $\frac{m}{s}$. Such a motion is called non-uniform motion.
3. A body in non-uniform acceleration also covers unequal displacements in equal intervals of time.