Question

A car increases its speed from 20 km/h to 50 km/h in 10 second find its acceleration

Answer 1

Given :

▪ Initial speed = 20kmph

▪ Final speed = 50kmph

▪ Time interval = 10s

To Find :

▪ Acceleration of car.

Concept :

↗ Acceleration is defined as the rate of change in speed.

↗ It is a vector quantity.

↗ It has both magnitude as well as direction.

↗ It can be positive, negative ot zero.

↗ SI unit : m/s²

Mathematically,

$\bigstar\:\underline{\boxed{\bf{\pink{a=\dfrac{v-u}{t}}}}}$

where,

a denotes acceleration

v denotes final speed

u denotes initial speed

t denotes time

Conversion :

✴ 1kmph = 5/18mps

✴ 20kmph = 20×5/18 = 5.56mps

✴ 50kmph = 50×5/18 = 13.89mps

Calculation :

$\dashrightarrow\sf\:a=\dfrac{v-u}{t}\\ \\ \dashrightarrow\sf\:a=\dfrac{13.89-5.56}{10}\\ \\ \dashrightarrow\sf\:a=\dfrac{8.33}{10}\\ \\ \dashrightarrow\underline{\boxed{\bf{\gray{a=0.83\:ms^{-2}}}}}\:\blue{\bigstar}$

Answer 2

Answer:

Explanation: initial velocity /speed of the car, u = 20km/hr

Final velocity of the car,v =50 km/hr

Total time taken=10s

Acceleration= (v-u)/t

By substituting the value mentioned above in this formula we get

(50-20)km/hr÷10s= 3km/hr²