Question

A particle starts from rest and moves with an acceleration of a = [ 4 + ( t - 3)] m/s², where t is in seconds. Find the velocity of the object at t = 4 sec.​

Answer 1

Answer:

20 m/s

Explanation:

Given:

• Initial velocity = u = 0 m/s
• Time = t = 4 seconds
• Acceleration = a = (4+(t-3)) m/s²

To find:

• Final velocity of the object (v)

As in the above case, t = 4 seconds,

a = 4+(4-3)

a = 4+1

a = 5 m/s²

Using first equation of motion:

V=u+at

V=0+5×4

V=0+20

V=20 m/s

The final velocity of the object is equal to 20 m/s

Answer 2

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

$\green{\tt{\therefore{Velocity\:after\:4\:sec=20\:m/s}}}$

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

$\green{\underline \bold{Given : }} \\ \tt: \implies Acceleration(a) = (4 + (t - 3)) { \: m/s}^{2} \\ \\ \tt: \implies Time(t) = 4 \: sec \\ \\ \red{\underline \bold{To \: Find : }} \\ \tt: \implies Velocity _{(at \: t = 4)} =?$

• According to given question :

$\tt \circ \: Acceleration = (4 + (t - 3)) =4 + 4 - 3 = 5 \: { m/s}^{2} \\ \\ \tt \circ \: Initial \: velocity = 0 \: m/s \\ \\ \bold{As \: we \: know \: that } \\ \tt: \implies v = u + at \\ \\ \tt: \implies v =0 + 5 \times 4 \\ \\ \tt: \implies v = 0 + 20 \\ \\ \green{\tt: \implies v =20 \: m/s} \\ \\ \green{\tt \therefore Velocity \:after \: 4 \: sec \: is \: 20 \: m/s}$