Mass ..68kg
f = 59N
a =?
f = mA
59 = 68×A
' 68×A = 59
so,A = 59/68 =0.8676470588m/s2...

Given:
Mass of the runner (m) = 68 kg
Force exerted by the runner (F) = 59 N

Acceleration:
Acceleration (a) is defined as the rate of change of velocity of an object. It can be calculated using Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. The formula for acceleration is:

a = F/m

where
a = acceleration,
F = force, and
m = mass.

Calculating the acceleration:
Using the given values, we can substitute them into the formula to calculate the acceleration:

a = 59 N / 68 kg

Simplifying the calculation:
Dividing 59 N by 68 kg gives us:

a ≈ 0.8676 m/s²

Therefore, the acceleration of the runner is approximately 0.8676 m/s².

Explanation:
When a force is applied to an object, it causes the object to accelerate. In this case, the runner exerts a force of 59 N. The acceleration of the runner depends on both the force exerted and the mass of the runner. The greater the force or the smaller the mass, the greater the acceleration.

In the given scenario, since the mass of the runner is 68 kg and the force exerted is 59 N, we can calculate the acceleration using the formula a = F/m. By substituting the values into the formula, we find that the acceleration of the runner is approximately 0.8676 m/s².

This means that for every second the runner runs, their velocity will increase by 0.8676 m/s in the direction of the applied force. The magnitude of the acceleration indicates how quickly the runner's velocity is changing.