Question

A car going 50mph accelerates to pass a truck. five seconds later the car is going 80mph. calculate the acceleration of the car.

Answer 1

Acceleration is the rate of change of the velocity of an object that is moving. This value is a result of all the forces that is acting on an object which is described by Newton's second law of motion. Calculation of such is straightforward, if we are given the final velocity, the initial velocity and the total time interval. We can just use the kinematic equations. Fortunately, we are given these values. So, we calculate as follows:

acceleration = v - v0 / t
acceleration = (80 mph - 50 mph) ( 1 h / 3600) / 5 s
acceleration = 1.67 x 10^-3 m / s^2 

Therefore, the acceleration of the car is 1.67 x 10^-3 m / s.

Answer 2

Answer:

The acceleration of the car is $2.68\ m/s^2$.

Explanation:

Given that,

Initial speed of the car, u = 50 mph

Since, 1 mph = 0.44704 m/s

u = 22.35 m/s

Final speed of the car, v = 80 mph = 35.76 m/s                    

Time, t = 5 s

To find,

The acceleration of car.

Solution,

The rate of change of velocity of an object is equal to its acceleration. Its formula is given by :

$a=\dfrac{v-u}{t}$

$a=\dfrac{35.76-22.35}{5}$

$a=2.68\ m/s^2$

So, the acceleration of the car is $2.68\ m/s^2$.