Force = mass * acceleration
F = ma
8 N = 2 kg * a
8 = 2a
2a = 8
a = 8/2 = 4
acceleration = 4 m/s²
Answer:
Average velocity is 0.296 m/s.
Average speed is 4.0 m/s.
Explanation:
Given:
Distance of the circular track is, 
Number of laps ran is, 
Time taken for the run is, 
Now, total distance covered in 5.4 laps = 
Also, since the path is a circle, the final position of the athlete after 5.4 laps will be 0.4 of 400 m ahead of the starting point.
Distance covered in 0.4 laps is, 
Therefore, the displacement of the athlete will be 160 m as the athlete is 160 m ahead of the starting point and displacement depends on the initial and final points only.
Now, average velocity is given as:

Average speed is the ratio of total distance covered to total time taken.
So, average speed = 
We will start from the definition of power in terms of the Force. Power could be described as the change of energy in an instant of time. Considering that Energy is the product between the Force and the distance traveled we would arrive at the expression


Here,
F = Force
h = Height
t = Time
As there is no external force, apart from the force of gravity, and this, is constant during the course of the object we will also have to be constant power and therefore this during its course will be the same. The correct answer is (1)