Question

If a body is at acceleration of 16 m/s.It its initial velocity is 72 km/hr.Find its final velocity after 16 seconds?

Answer 1

HEYA!!
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Applying first equation of motion-

$\boxed{V = u + at}$

final velocity (v) = ?

initial velocity (u) =72 km/hr=72×5/18=20 m/s

[1 km/hr=5/18 m/s]

acceleration (a) = 16m/s^2

time(t) = 16 sec.

so,

v = 20 + 16m/s^2 × 16

v = 20 + 256

v = 276km/hr.

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Answer 2

Given :

Initial velocity = 72 km/hr .

Convert km/hr to m/s

We know that 1 km = 1000 m .

We also know that 1 hr = 60×60 s ⇒ 3600 s .

1 km / hr ⇒ 1 km / 1 hr

⇒ ( 1000 m ) / ( 3600 s )

⇒ ( 10/36 ) m/s

⇒ ( 5/18 ) m/s .

If 1 km/hr = 5/18 m/s ,

then 72 km/hr = 72 × 5/18 m/s

⇒ 72 km/hr = 4 × 5 m/s

⇒ 20 m/s

Acceleration = 16 m/s² [ typing mistake ]

Time ( t ) = 16 s .

Final velocity ( v ) = ?

Acceleration ( a ) = 16 m/s² .

Initial velocity ( u ) = 20 m/s .

By the Laws of motion we have :

v = u + a t

⇒ v = 20 m/s + 16 m/s² × 16 s

⇒ v = 20 m/s + 256 m/s

⇒ v = 276 m/s

The final velocity is 276 m/s .