Question

A car starting from rest (i.e. initial velocity = 0.0 m/s), moves in the positive X-direction with a constant average acceleration = 3.1 m/s2 for 7.9 s. What will be its velocity at that time.

Answer 1

The car's final velocity after accelerating from rest at 3.1 m/s^2 for 7.9 seconds will be 24.49 m/s.

Step-by-step explanation:

To calculate the velocity of a car that starts from rest and accelerates at a constant rate, you can use the formula:

v = u + at

where v is the final velocity, u is the initial velocity, a is the acceleration and t is the time.

In the case of the car starting from rest (u = 0.0 m/s) and accelerating at 3.1 m/s2 for 7.9 s, the formula simplifies to:

v = 0 + (3.1 m/s2)(7.9 s) = 24.49 m/s

So, the car's velocity after 7.9 seconds will be 24.49 m/s in the positive X-direction.

Answer 2

Final speed of the car, v = 24.49 m/s

Step-by-step explanation:

It is given that,

Initial velocity of the car, u = 0

Acceleration,
`a=3.1\ m/s^2`

Time taken, t = 7.9 s

We need to find the final velocity of the car. Let it is given by v. It can be calculated using first equation of motion as :

`v=u+at`

`v=0+3.1* 7.9`

v = 24.49 m/s

So, the final speed of the car is 24.49 m/s. Hence, this is the required solution.