Question

A body starts from rest and moves with acceleration of 4ms² in what time the body will acquire a speed of 80m/s? how much distance will it travel in this time

Answer 1

time is in the image

and
distance

= v2-u2/2a

=6400/2×4

=800m

hope you are satisfied with my answer

Answer 2

$\blue{\bold{\underline{\underline{Answer:}}}}$

$\green{\therefore{\text{Time\:taken=20\:sec}}}$

$\green{\therefore{\text{Distance\:travelled=800\:m}}}$

$\orange{\bold{\underline{\underline{Step-by-step\:explanation:}}}}$

• In the given question information given about a body starts moving from rest and moves with an acceleration 4m/s^2.

• We have to find time taken to attains speed of 80 m/s and distance travelled during this time interval.

$\green{\underline\bold{Given :}} \\ :\implies \text{Initial\:velocity(u)=0\:m/s} \\ \\ :\implies \text{Acceleration(a)= 4\:m}/s^{2}\\ \\ :\implies \text{Final\:velocity(v)= 80\:m/s}\\ \\ \red{\underline \bold{To \: Find : }} \\ :\implies \text{Time\:taken(t)= ?}\\\\ :\implies \text{Distance(s)=?}$

• According to given question :

$\bold{Using \: first \: equation \: of \: motion : } \\ : \implies v = u + at \\ \\ : \implies 80= 0 +4\times t \\ \\ : \implies t= \frac{80}{4} \\ \\ \green{ : \implies {\text{t= 20\:sec}}}$

$\bold{Using \: second \: equation \: of \: motion} \\ : \implies s = ut + \frac{1}{2} a {t}^{2} \\ \\ : \implies s = 0 \times 4 + \frac{1}{2} \times 4 \times {20}^{2} \\ \\ : \implies s = 2 \times 400 \\ \\ \green{ : \implies \text{s =800m}}$