Question

Find the required time for a car to move 98 m if it starts from rest and acceleration at 40 m/s2?

Answer 1

Answer:

The time required for the car is 2.214 seconds.

Explanation:

• This can be solved easily by using the third equation of motion which is as follows:

   s=u×t+1/2(a×t^2), Where 's' is the total distance covered by the car, 'u' is the initial velocity of the car, 't' is the time required to cover the distance 's' and 'a' is the acceleration of the car.

• NOTE: the above equation is only valid for constant acceleration which has been fulfilled by the question as nothing is mentioned about the change in acceleration.
• let's just simply put the values in the equation as all the given values are in similar units.
• given , s=98 m , u=0(as the car started from rest) , t=t(let) , a=40 m/s^2
• Thus, 98=0×t+1/2(40×t^2)
• on solving, we get t as 2.21359436 which on rounding off up to 3 decimal places, gives us our answer as 2.214 seconds

Answer 2

Answer:

2.2135 Seconds

Explanation:

By using the second equation of motion:   S=ut+1/2at2

We have given: -

• Displacement = 98 m

• Acceleration(a) = 40 m/s2

• Initial Velocity(u) = 0          (Because, Car starts from rest)

We have to find the time for a car to move 98 m.

By putting all the given values in the formula, we get the time = 2.2135 Seconds