Question

A ball is thrown upward from the edge of a cliff with an initial velocity of $8\text{m/s}$. How fast will it go at $0.5\text{sec}$ later.
[Take $g=10{\text{m/s}}^2$]

• A. $2\text{m/s}$
• B. $3\text{m/s}$
• C. $4\text{m/s}$
• D. $1\text{m/s}$

Answer 1

The correct option is B $3\text{m/s}$

The instant velocity at the time $0.5\text{sec}$ from the start of the motion is given as
$v=u+at$
$\Rightarrow v=u-gt$
$\Rightarrow v=8-10\times 0.5$
$\Rightarrow v=3\text{m/s}$