Question

a car acquires a velocity of 72km/h in 10 sec starting from rest . find the distance travelled by this time​

Answer 1

Answer:

Hey there !

Initial Velocity = u = 0

Final velocity = v = 72 km/hr = 72 x 5/18 = 20 m/s

Time = t = 10 sec

Acceleration = a

Equation of motion :-

v = u + at

20 = 0 + 10a

a = 20/10

a = 2 m/s²

displacement = distance traveled = s

Equation of motion :-

v² - u² = 2as

20² = 2 × 2 × s

400 = 4s

s = 400/4

s = 100 m

Average velocity = displacement / time

= 100 / 10

= 10 m/s

Hope this helps you !

Answer 2

Required Answer :

The distance travelled by the car = 100 m

Given :

• Initial velocity of the car = 0 m/s
• Final velocity of the car = 72 km/h
• Time = 10 seconds

To find :

• Distance travelled by the car

Solution :

Firstly, let's covert the final velocity of the car from km/h into m/s by multiplying the value by 5/18.

⇒ Final velocity = 72 × 5/18

⇒ Final velocity = 4 × 5

⇒ Final velocity = 20 m/s

Now, to calculate the distance travelled by the car, firstly we will calculate the acceleration.

First equation of motion :

• v = u + at

where,

• v = Final velocity
• u = Initial velocity
• a = Acceleration
• t = Time

Substituting the given values :

⇒ 20 = 0 + (a)(10)

⇒ 20 = 10a

⇒ 20/10 = a

⇒ 2 = a

Acceleration of the car = 2 m/s²

Now, let's calculate the distance travelled by the car by using the third equation of motion.

Third equation of motion :

• v² - u² = 2as

where,

• v = Final velocity
• u = Initial velocity
• a = Acceleration
• s = Distance

Substituting the given values :

⇒ (20)² - (0)² = 2(2)(s)

⇒ 400 = 4 × s

⇒ 400/4 = s

⇒ 100 = s

Therefore,

• The distance travelled by the car = 100 m