Question

initial speed of an object 4 meter per sec and final speed is 8 meter per sec . calculate average speed​

Answer 1

Answer:

This can be calculated by the formula

s = ut + 1/2at^2

Thus is the 2nd equation of motion.

Where s is displacement(distance as in straight path), u is the initial velocity, a is acceleration , t is time period.

Here u = 10m/s, a=4m/s^2, t=8s.

So here distance = 10 * 8 + 1/2*4*8*8

= 80+ 128 m

= 208

Thank you.

Answer 2

Answer:

The average speed of the journey is 6 m/sec.

Given:

Initial speed , u = 4m/sec

Final Speed , v = 8 m/sec

To Find:

Find the average speed of the journey.

Solution:

Let the total distance traveled = S metres

Applying equation of motion,

v = u + at

8 = 4 + at

at = 4 ..................................(1)

Applying second equation of motion,

S = ut + 1/2at²

S = t ( u + 1/2at)

S/t = u +1/2at

As we know that the average speed = total distance/ total time

average speed = S/t

average speed = ( u +1/2at)

average speed = 4 +1/2(4)

average speed = 6

Hence the average speed of the journey is 6 m/sec.