The scenario involves using mechanical advantage is: two pulleys attached to the rafter, two pulleys attached to the weight, one end attached to the rafter, and someone standing on the rafter pulling the rope.

When sound travels through water rather than air, the wavelength increases because the speed of sound is higher in water while the frequency stays the same.

First, we need to calculate the acceleration required to achieve this velocity. We can use the formula a = v/t, where v is the final velocity and t is the time taken to reach that velocity.
a = v/t = 27 m/s / 3 s = 9 m/s^2
Now that we know the acceleration required, we can use the formula F = ma to calculate the force required:
F = ma = 10 kg * 9 m/s^2 = 90 Newtons.

Katie is riding her bike to the store. The store is 700 meters from her house. If it takes Katie 140 seconds to reach the store, her average speed is 5.0 m/s. 700 / 140 = 5.0m/s.