MCQ
The posttion of an object moving along $x$ -axis ts given by $x=a+b t^{2}$ where $a=8.5\; \mathrm{m}, b=2.5 \;\mathrm{m} \mathrm{s}^{-2}$ and $t$ is measured in seconds. What is the velocity at $t=0\;s$ and $t=2.0 \;s$?
- A$10 \;\mathrm{m} \mathrm{s}^{-1}\;,\;20 \;\mathrm{m} \mathrm{s}^{-1}$
- B$0 \;\mathrm{m} \mathrm{s}^{-1}\;,\;20 \;\mathrm{m} \mathrm{s}^{-1}$
- ✓$0 \;\mathrm{m} \mathrm{s}^{-1}\;,\;10 \;\mathrm{m} \mathrm{s}^{-1}$
- D$0 \;\mathrm{m} \mathrm{s}^{-1}\;,\;0 \;\mathrm{m} \mathrm{s}^{-1}$
