question_answer

A pebble is thrown vertically upwards with a speed of\[\text{2}0\text{m}{{\text{s}}^{-\text{1}}}\]. How high will it be after 2seconds? (Take \[\text{g}=\text{1}0\text{m}{{\text{s}}^{-\text{2}}}\])

Answer:

\[u=20\,m{{s}^{-1}},\,\,g=10m{{s}^{-2}},\,\,t=2s,\,\,h=?\] \[h=ut-\frac{1}{2}g{{t}^{2}}=20\times 2-\frac{1}{2}\times 10\times {{(2)}^{2}}\] \[=40-20=20m.\]