Question

a car starting from rest and picks up a velocity of 20 km per hour in 10 second calculate acceleration of a car... (chang the km to mtrs)​

Answer 1

Answer:

• -0.55 m/s² is the required acceleration.

Explanation:

Given:-

• Initial velocity ,u = 20km/h = 20× 5/18 = 100/18 = 5.5m/s
• Final velocity ,v = 0m/s
• Time taken ,t = 10 s

To Find:-

• Acceleration ,a ?

Solution:-

We have to calculate the acceleration of the car . As we know that acceleration is defined as the rate of change of velocity at per unit time .

✇ a = v-u/t

where,

• v is the final velocity
• a is the acceleration
• u is the initial velocity
• t is the time taken

Substitute the value we get

➺ a = 0-5.5/10

➺ a = -5.5/10

➺ a = -0.55 m/s²

here ,

negative sign show retardation

• Hence, the acceleration of the car is -0.55m/s.

Answer 2

Answer:

Correct Question :-

• A car starting from rest and picks up a velocity of 20 km/h in 10 seconds. Calculate the acceleration of a car.

Given :-

• A car starting from rest and picks up a velocity of 20 km/h in 10 seconds.

To Find :-

• What is the acceleration of a car.

Formula Used :-

$\clubsuit$ Acceleration Formula :-

$\longmapsto \sf\boxed{\bold{\pink{a =\: \dfrac{v - u}{t}}}}$

where,

• a = Acceleration
• v = Final Velocity
• u = Initial Velocity

Solution :-

$\bigstar$ Final Velocity :-

$\implies \sf\bold{\green{0\: m/s}}$

$\bigstar$ Initial Velocity :

$\implies \sf 20\: km/h$

$\implies \sf 20 \times \dfrac{5}{18}\: m/s$

$\implies \sf \dfrac{100}{18}\: m/s$

$\implies \sf\bold{\green{5.55\: m/s}}$

$\bigstar$ Time Taken :

$\implies \sf\bold{\green{10\: seconds}}$

Hence, we get :

• Initial Velocity = 5.55 m/s
• Final Velocity = 0 m/s
• Time Taken = 10 seconds

According to the question by using the formula we get,

$\dashrightarrow \sf a =\: \dfrac{0 - 5.55}{10}$

$\dashrightarrow \sf a =\: \dfrac{- 5.55}{10}$

$\dashrightarrow \sf a =\: \dfrac{- 555}{10 \times 100}$

$\dashrightarrow \sf a =\: \dfrac{- 555}{1000}$

$\dashrightarrow \sf\bold{\red{a =\: - 0.555\: m/s^2}}$

$\therefore$ The acceleration of a car is - 0.555 m/s².

[Note : The negetive (- ve) signs indicate the velocity is decreasing. ]