Question

A racecar travling on a straight part of a track has an initial velocity of 15.0 m/s. If the car accelerates at 3.00 m/s/s, how long until the car reaches 30.0 m/s?

Answer 1

Given:-

• Initial velocity ,u = 15m/s

• Acceleration ,a = 3m/s²

• Final velocity ,v = 30m

To Find:-

• Time taken by the car ,t.

Solution:-

By using 1st equation of motion we get

→ v = u+at

Substitute the value we get

→ 30 = 15 + 3×t

→ 30-15 = 3×t

→ 15 = 3×t

→ t = 15/3

→ t = 5s

∴ The time taken by the car is 5 second.

Additional Information!!

Some equation of motion are

⟹ v = u +at

⟹s = ut +1/2at².

⟹ v² = u² + 2as

Here,

v is the final velocity

u is the initial velocity

a is the acceleration

s is the displacement or Distance

t is the time taken

Answer 2

Given :

• Initial Velocity (u) = 15 m/s

• Acceleration (a) = 3 m/s²

• Final Velocity (v) = 30 m/s

To Find :

• Time taken by the car = ?

Solution :

• By using 1st Equation of motion we get :]

➺ v = u + at

➺ 30 = 15 + (3)t

➺ 30 - 15 = 3t

➺ 15 = 3t

➺ t = 15/3

➺ Time = 5 seconds.

Therefore,time taken by the car is 5 seconds.