Download App

PHYSICS CH 2 Motion — Science STD 9 — Question

Tamilnadu BoardEnglish MediumSTD 9SciencePHYSICS CH 2 Motion4 Marks
Question
Define acceleration and state its SI unit for motion along a straight line, when do we consider the acceleration to be (i) positive (ii) negative? Give an example of a body in uniform acceleration.
✓

Answer

  • Answer: Acceleration is the rate of change of velocity with respect to time or it is the rate of change of velocity in unit time. It is a vector quantity. The $SI$ unit of acceleration is $ms ^{-2}$
    Acceleration $=$ Change in velocity/time
    $=($ Final velocity - initial velocity $) /$ time
    \[
    a =\frac{v-u}{t}
    \]
    If $v>u$, then ' $a$ ' is positive. If final velocity is greater than initial velocity, the velocity increase with time, the value of acceleration is positive.
    If $v<u$, then a is negative. If final velocity is less than initial velocity
    Example: The motion of a freely falling body and vertically thrown up body are the examples of uniform acceleration.
    The motion of ball rolling down on an inclined plane is another example.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "[4 Mark Questions]" from PHYSICS CH 2 Motion→PHYSICS CH 2 Motion — all question types→Science STD 9 question papers→Tamilnadu Board STD 9 question papers→Tamilnadu Board question paper generator→

Similar questions

Derive an expression for Pressure due to the Liquid column.
→
Explain the history of computers.
→
Explain the classification of acids based on their basicity.
→
Name various food additives and explain their functions.
→
Write SI units for the fundamental quantity.
→
Write notes on the properties of acids.
→
Tabulate Differences between mixtures and compounds.
→
Write notes on the properties of bases. .
→
Distinguish e.m.f and potential difference.
→
A train is travelling at a speed of $90 kmh ^{-1}$. Brakes are applied so as to produce a uniform acceleration of$0.5 ms ^{-2}$, find how far the train will go before it is brought to rest.
→