Question

A carvincreases its speed from 20 kilometre per hour to 15 km per hour in seconds.a what is the acceleration?​

Answer 1

$\bold{\Large\purple{\boxed{{{Hey \: Mate..!!}}}}}$

$\bold{\Huge\red{\boxed{{{Answer}}}}}$

$\boxed{ \boxed{ \bold{ \large{✒ \: 0.83 \: m {s}^{ - 2}}}}}$

✒ Initial velocity (u) = 20 km/h

$\bold{\large{ = > \frac{20 \times 1000}{60 \times 60} }}$

$\bold{\large{ = > \frac{50}{9} \: m {s}^{ - 1} }}$

✒ Final velocity (v) = 50 km/h

$\bold{\large{ = > \frac{50\times 1000}{60 \times 60} }}$

$\bold{\large{ = > \frac{125}{9} \: m {s}^{ - 1} }}$

✒ Time (t) = 10 seconds

$\bold{\Huge\blue{\boxed{{{To\: Find}}}}}$

✒ Acceleration of car = ?

$\bold{\Huge\green{\boxed{{{Solution}}}}}$

• Initial velocity (u) = 50/9 m/s
• Final velocity (v) = 125/9 m/s
• Time (t) = 10 sec

As we know,

Acceleration =

$\boxed{\boxed{\boxed{ \bold{\frac{Initial \: velocity \: + \: Final \: v elocity}{time} }}}}$

$\boxed{\boxed{ \large{ = > a = \frac{v - u}{t} }}}$

Now substituting the values ,

$\boxed{\boxed{ \large{ = > a = \frac{ \frac{125}{9} - \frac{50}{9} }{10} }}}$

$\boxed{\boxed{ \large{ = > a = \frac{75}{9 \times 10} }}}$

$\boxed{\boxed{ \large{ = > a = 0.83 \: m {s}^{ - 2} }}}$

Hence the acceleration of the car is 0.83 m/s².