A skateboarder, starting from rest, rolls down a 11.5-m ramp. When she arrives at the bottom of the ramp her speed is 6.95 m/s.

85

To find the skateboarder's acceleration, we can use the equation of motion:

v^2 = u^2 + 2as

Where:
v = final velocity (6.95 m/s)
u = initial velocity (0 m/s, since she starts from rest)
a = acceleration (unknown)
s = displacement (11.5 m)

Rearranging the equation, we get:

a = (v^2 - u^2) / (2s)

Substituting the given values, we have:

a = (6.95^2 - 0^2) / (2 * 11.5)

a = 48.2025 / 23

a ≈ 2.1 m/s^2

Therefore, the skateboarder's acceleration is approximately 2.1 m/s^2.