Question

a car at rest accelerates uniformly to a speed of 144km/have in 20 sec how much distance is covered by the car

Answer 1

Answer:

distance covered = 400 meter

Step by step explanations :

given that,

a car at rest accelerates uniformly to a speed of 144 km/h in 20 sec

here,

initial velocity of the car = 0 m/s

[because car was initially at rest]

final velocity of the car = 144 km/h

= 144 × 1000 m/3600 s

= 40 m/s

time taken to accelerate = 20 seconds,

let the distance covered by the car during acceleration be s

now,

we have,

initial velocity(u) = 0 m/s

final velocity(v) = 40 m/s

time taken(t) = 20 seconds

by the equation of motion,

v = u + at

putting the values,

40 = 0 + a(20)

20a = 40

a = 40/20

a = 2 m/s²

so,

acceleration of the car ⛟ = 2 m/s²

also,

S = ut + ½ at²

again putting the values,

S = 0(20) + ½ × 2 × 20 × 20

S = 400 m

so,

distance covered by the car during acceleration

= 400 meter

Answer 2

Answer:

Explanation:

Given :-

Final Velocity of a car, v = 144 km/h = 5/18 × 144 =  40m/s

Initial Velocity of a car, u = 0

Time taken by car, t = 20 seconds

To Find :-

Distance is covered by the car.

Formula to be used :-

Newton's 1st equation i.e v = u + at

Newton's 2nd equation i.e s = ut + 1/2 at²

Solution :-

Putting all values, we get

⇒ v = u + at

⇒ 40 = 0 + 20 × a

⇒ a = 2 m/s²

Putting acceleration value on 2nd equation

⇒ S = ut + 1/2 at²

⇒ S = 1/2 x 2 x (20)²

⇒ S = 400 m

Hence, the distance is covered by the car is 400 m.