Question

. A car is moving with 18 km/h. It accelerates at 2m/s2

find the

displacement if it attains the final velocity of 72 km/h?​

Answer 1

Explanation:

s=93.75m

hope it helps you

Answer 2

Answer:

93.75 m

Explanation:

As per the provided information in the given question, we have :

• Initial velocity (u) = 18 km/h
• Acceleration (a) = 2 m/s²
• Final velocity (v) = 72 km/h

We are asked to calculate the displacement.

Before commencing the steps, let's first convert the velocities in its standard form, that is m/s.

★ Converting initial velocity in m/s :

$\longmapsto \rm { u = 18 \; kmh^{-1} }$

• 1 km/h = 5/18 m/s

$\longmapsto \rm { u = \Bigg ( 18 \times \dfrac{5}{18} \Bigg ) \; ms^{-1} }$

$\longmapsto \bf { u = 5 \; ms^{-1} }$

★ Converting final velocity in m/s :

$\longmapsto \rm { v = 72 \; kmh^{-1} }$

1 km/h = 5/18 m/s

$\longmapsto \rm { v = \Bigg ( 72 \times \dfrac{5}{18} \Bigg ) \; ms^{-1} }$

$\longmapsto \rm { v = \Big ( 4 \times 5 \Big ) \; ms^{-1} }$

$\longmapsto \bf { v = 20 \; ms^{-1} }$

Now, by using the third equation of motion:

$\longmapsto \bf { v^2 - u^2 = 2as}$

• v denotes final velocity
• u denotes initial velocity
• a denotes acceleration
• s denotes distance/displacement (displacement, when motion in is straight line)

$\longmapsto \rm { (20)^2 - (5)^2 = 2(2)s}$

$\longmapsto \rm { 400-25 = 4s}$

$\longmapsto \rm { 375 = 4s}$

$\longmapsto \rm {\dfrac{ 375 }{4}= s}$

$\longmapsto \bf { 93.75 \; m = s}$

∴ Displacement is 93.75 m.

$\rule{200}2$

Additional Information :

Three equations of motion :

$\boxed{ \begin{array}{cc} \pmb{\sf{ \quad \: v = u + at \quad}} \\ \\ \pmb{\sf{ \quad \: s= ut + \cfrac{1}{2}a{t}^{2} \quad \: } } \\ \\ \pmb{\sf{ \quad \: {v}^{2} - {u}^{2} = 2as \quad \:}}\end{array}}$

• v denotes final velocity
• u denotes initial velocity
• a denotes acceleration
• t denotes time
• s denotes distance/displacement