Question

A body is started from rest and reached the velocity 15m/s in 7sec. Find acceleration.​

Answer 1

Answer:

4 m/sec

v

i

=10 m/s and v

f

=20 m/s

Acceleration of the body =

5

20−10

m/s

2

a=2 m/s

2

Velocity of the body at t=−3 sec

v=u+at

v=10−2×3

v=4 m/s

Answer 2

Answer:

2.1 m/s²

Explanation:

As per the provided information in the question, we have been provided with the initial velocity, final velocity and time taken by the body. We have,

• Initial velocity (u) = 0 (As it starts from rest)
• Final velocity (v) = 15m/s
• Time taken (t) = 7s

We've been asked to asked to calculate the acceleration of the body.

Acceleration is defined as the change in velocity for a certain period of time or the rate of change in velocity. we'll calculate the acceleration of the car using the first equation of motion. It is given by,

$\begin{gathered} \twoheadrightarrow \quad \boxed{ \pmb{ \sf{a = \frac{v - u}{t} }}} \\ \end{gathered}$

Where,

• a denotes acceleration
• v denotes final velocity
• u denotes initial velocity
• t denotes time

$\begin{gathered}\twoheadrightarrow\sf a = \dfrac{15 - 0}{7}\end{gathered}$

$\begin{gathered}\twoheadrightarrow\sf a = \dfrac{15}{7}\end{gathered}$

$\begin{gathered} \twoheadrightarrow\sf{a = 2.1 ms^{-2}}\end{gathered}$

∴ Acceleration of the body is 2.1 m/s².

More to know!

• $\begin{gathered}\qquad \sf \: ( I )\: v = u + at\:\\\\\end{gathered}$

• $\begin{gathered}\qquad \sf \: ( II ) \: s = ut + \dfrac{1}{2}at^2\:\:\:\\\\\end{gathered}$

• $\begin{gathered}\qquad \sf \: ( III ) \:\:v^2- u^2 = 2as \:\\\\\end{gathered}$

• $\begin{gathered}\qquad \sf \: ( IV ) \:\:\:s = \dfrac{1}{2}(u + v) t \:\\\\\end{gathered}$