Question

Given the formula v2 = u? + 2as, find the value of v when u = 15, a = 9.81 and s = 14.45.
Round off your answer to 3 significant figures.
​

Answer 1

$\underline\green{\bold{EXPLANATION}}$

$\underline\red{\bold{✓GIVEN}}$

• intial Velocity (u) = 15 m/s

• Acceleration (a) = 9.81 m/s2

• Distance (s) = 14.45 m

$\underline\red{\bold{✓FORMULA}}$

${v}^{2} = {u}^{2} + 2as$

where,

v = final velocity

u = Initial Velocity

a = acceleration

s = distance

$\underline\red{\bold{✓SOLUTION}}$

${v}^{2} = {(15)}^{2} + 2 \times 9.81 \times 14.45 \\ \implies \: {v}^{2} = 225 + 283.509 \\ \implies {v}^{2} = 508.509 \\ \implies \: v = \sqrt{508.509} \\ \implies \: v = 22.550144123707$

Now Round off 22.550144123707 to 3 significant figures = 22.55