A 65.5 kg high jumper leaves the ground with a vertical velocity of 8.1 m/s.

How high can he jump? The acceleration of gravity is 9.8 m/s2 .

Hmm, I may be overlooking something here, unless the mass is irrelevant, but I drew Y0=0 V0=8.1m/s VF=0m/s( because the jumper reached Yf stops and comes back down toward earth) and a=9.8m/s^2 so you're looking for Y final position

I used Vf^2=V0^2+2a(Yf-Y0) since vf=0 and Y0=0 rearrange to solve for Yf
-Vo^2/2a=yf
-8.1m/s)^2/2(9.8m/s^2)= Yf
65.61m^2/s^2/19.6m/s^2
Yf=3.35m .....
The only reason I could think of that the mass is here is because F=ma

The mass is irrelevant

(1/2) m v^2 = m g h
note mass cancels
h = (1/2) v^2 / g = 3.347 = 3.35 meters
correct

To find the maximum height the high jumper can reach, we'll use the equations of motion and the principles of conservation of energy.

Step 1: Determine the initial velocity and acceleration
The given initial velocity (u) of the high jumper is 8.1 m/s.
The acceleration due to gravity (g) is -9.8 m/s^2 since it acts in the opposite direction of the jump.

Step 2: Calculate the time taken to reach the highest point
At the highest point of the jump, the vertical velocity (v) will be 0 m/s. We can use the equation of motion:
v = u + at

Rearranging the equation to solve for time (t):
0 = 8.1 - 9.8t
9.8t = 8.1
t = 8.1 / 9.8
t ≈ 0.826 seconds

Step 3: Calculate the maximum height
The maximum height (h) can be calculated using the equation:
h = ut + (1/2)gt^2

Substituting the values:
h = 8.1(0.826) + (1/2)(-9.8)(0.826)^2
h ≈ 6.688 + (-3.211)
h ≈ 3.477 meters

Therefore, the high jumper can jump a maximum height of approximately 3.477 meters.

To determine how high the high jumper can jump, we can use the principles of physics and motion equations. Specifically, we can use the kinematic equation that relates the final velocity, initial velocity, acceleration, and displacement:

(vf)^2 = (vi)^2 + 2ad

Where:
- vf is the final velocity (which in this case would be 0 m/s when the high jumper reaches the highest point of the jump)
- vi is the initial velocity (8.1 m/s)
- a is the acceleration due to gravity (-9.8 m/s^2)
- d is the displacement (which represents the maximum height reached by the high jumper)

Since the final velocity at the highest point is 0 m/s, we can rearrange the equation:

0 = (8.1)^2 + 2(-9.8)d

Now, we can solve for d:

-81.6 = -19.6d

Dividing both sides of the equation by -19.6:

d = -81.6 / -19.6

d ≈ 4.16 meters

Therefore, the high jumper can jump approximately 4.16 meters high.