Question

A boy starts from rest and moves with uniform acceleration of 5m/s2 for 8 sec
From that time acceleration ceases.find the distance covered in 12sec starting from rest

Answer 1

Answer:

320 metres

Explanation:

Given :

• Initial velocity = u = 0 m/s
• Acceleration = a = 5 m/s²
• Time taken = t = 8 seconds
• Acceleration ceases after 8 seconds

To find :

• Distance covered in 12 seconds starting from rest

Using first equation of motion:

V=u+at

V=0+5×8

V=0+40

V=40 m/s

Now using second equation of motion :

S=ut+½at²

S=0×8+½×5×8×8

S=0+160 metres

S=160 metres

Now it travels with 40 m/s for 4 seconds

Distance travelled = 40×4

Distance travelled = 160 metres

Total distance = 160+160

Total distance = 320 metres

The total distance covered is equal to 320 metres

Answer 2

✯✯ QUESTION ✯✯

A boy starts from rest and moves with uniform acceleration of 5m/s2 for 8 sec.From that time acceleration ceases.find the distance covered in 12sec starting from rest.

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✰✰ ANSWER ✰✰

$\implies\tt{Initial\:Velocity(u)=0\:m/s}$

$\implies\tt{Time\:Taken(t)=8\:sec }$

$\implies\tt{Acceleration(a)=5\:m/s}$

$\implies\tt{Final\:Velocity(v)=?}$

$\implies\tt{Distance\:travelled(s)=?}$

➥Using 1st Equation of Motion : -

$\implies\tt{\small{\boxed{\bold{\bold{\purple{\sf{v=u+at}}}}}}}$

➥Putting Values : -

$\implies\tt{v=0+(5)\times{(8)}}$

$\implies\tt{v=0+40}$

$\pink\longmapsto\:\large\underline{\boxed{\bf\orange{v}\green{=}\red{40m/s}}}$

➥Now ,

For Finding the distance travelled : -

➥Using 2nd Equation of Motion : -

$\implies\tt{\small{\boxed{\bold{\bold{\blue{\sf{s=ut+\dfrac{1}{2}{at}^{2}}}}}}}}$

➥Putting Values : -

$\implies\tt{s=0\times{8}+\dfrac{1}{2}\times{(5)}\times{{8}^{2}}}$

$\implies\tt{s=0+\dfrac{1}{2}\times{(5)}\times{{64}}}$

$\implies\tt{s=\dfrac{1}{\cancel{2}}\times{{\cancel{320}}}}$

$\red\longmapsto\:\large\underline{\boxed{\bf\green{s}\orange{=}\purple{160m.}}}$

➥Now ,

As the body travels 40m/s in 4 sec. For 8 seconds the distance travelled by it : -

$\implies\tt{40\times{8}}$

$\implies\tt{320m}$