Question

A particle accelerates from rest. The graph shows how the acceleration a of the particle
varies with time t


What is the speed of the particle at 1 = 6.0 s?

A. 0.5 ms
B.2.0 ms'
C. 9.0 ms'
D. 18 ms

Answer 1

Answer:

On the paper there's also a graph of a (y-axis) against t (x-axis) with a straight line passing through the axis origins (0,0). After I did it, I got the result C. 9.0 ms–1. According to the Markscheme my result is correct. But in my teacher's opinion this should be the wrong answer, while the correct one should be D. 18 ms–1.

We both did different calculations. I found speed after calculating the displacement (s = (1/2)at²) and then I just did v = s/t, while he just did v = at (inverse formula of a = v/t).

Hence answer is - -

Option -(c) - 9m/s

This thing left us kinda confused, because in this case acceleration increases along a straight line, according to the graph.