From the change of GPE into KE. Conservation of energy tells us this.
Add the KE increase and the work done against friction.
The final velocity is twice the average, or 3.0 m/s
The final KE is (1/2)*25*3^2 = 112.5 J
The friction work done is 6*3.8 = 22.8 J
hope this is correct
100% C . By size and distance
To find wave speed, you multiply the wavelength by the frequency. This means it is 8 times 11. This gives you 88. That means the answer is 88mm/s
