Aman of 65kg jumps in aswimming from atower of height 19.6m.he was found to go down in water by 2m and started raising up.find the average resistance in water?
To calculate the average resistance in water, we need to calculate the average force experienced by the person while going down and coming up in the water.
First, let's calculate the gravitational potential energy (GPE) when the person jumps from the tower:
GPE = mass * gravitational acceleration * height
= 65 kg * 9.8 m/s² * 19.6 m
= 12,887 Joules
Next, let's calculate the potential energy at the bottom when the person is 2m underwater:
Potential energy at the bottom = mass * gravitational acceleration * depth
= 65 kg * 9.8 m/s² * 2 m
= 1,274 Joules
Now, let's calculate the work done by the resistance force in water while the person is going down:
Work done = GPE at the start - Potential energy at the bottom
= 12,887 J - 1,274 J
= 11,613 Joules
Similarly, let's calculate the work done by the person to come back up:
Work done = GPE at the start - Potential energy at the bottom
= 12,887 J - 1,274 J
= 11,613 Joules
Since the work done is the same for both going down and coming up, we can take the average:
Average work done = (work done while going down + work done while coming up) / 2
= (11,613 J + 11,613 J) / 2
= 11,613 Joules
Finally, the average resistance force can be calculated using the formula:
Average resistance force = average work done / distance traveled
= 11,613 J / (2 m + 2 m)
= 2,903.25 Newtons
Therefore, the average resistance in water is approximately 2,903.25 Newtons.