Question

A body moving with uniform acceleration has a velocity of -11 cm/s when its x coordinate is 3.00 cm. If itsx coordinate 2 s later is -5 cm, what is the magnitude in cm/square of its acceleration?

Answer 1

Distance travelled, $s=-5-(+3)=-8cm$ Initial velocity, $u=-11cm/s$ time, $t=2s$
We use,
$$\begin{gathered} s=ut+\frac{1}{2}a{t}^2 \\ \Rightarrow -8=-11\times 2+\frac{1}{2}\times a\times 2^2 \\ \Rightarrow a=\frac{22-8}{2}=7 \end{gathered}$$
Therefore magnitude of acceleration in $cm/s^2$ is 7.