Answer:
for any object in motion , distance is always greater than displacement
The solution for this problem is:
Remember that this doesn’t depend on the mass of the child.
E = T + U = constant
E (maximum height) = T + U =U = mgh = mg[r - r· cos (Θ)]
E (bottom height) = T + U = T = ½mv² = mg[r - r · cos (Θ)]
v² = 2g[r – r · cos (Θ)]
v = √ (2g[r-r·cos(Θ)])
= √(2(9.8)[3 – 3 · cos (45°)])
= 4.15 m/s or 15 kph
