Question

A graph is plotted showing the velocity of a bus as a function of time. If the graph is a straight lines means that
(a) the bus started at rest.
(b) velocity was constant.
(c) acceleration was constant.
(d) acceleration was increasing.
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Answer 1

If the graph is a straight line, most may get the option (b) the answer as the velocity was constant since the acceleration is zero (The slope of a velocity - time graph gives acceleration).

But (b) is a wrong option as the graph is said to be 'just' a straight line but it's not said that the graph is parallel to time axis! Acceleration is zero only on this case. Many confuse on this.

If the velocity - time graph is a straight line it means the velocity of the bus gradually changes, increases or decreases, by the same rate after each unit time. This also means that the acceleration is a constant every time (the slope is constant for each point in the graph.)

Hence the correct answer is (c) acceleration was constant.

Answer 2

Answer:

(b)

Explanation: