They are called mechanical waves
To lift the bag straight up takes (F · D) = (45 · 1.2) = 54 joules of energy (work).
Moving the bag horizontally 'across' gravity requires no work.
It doesn't matter how far.
Answer:
76 m /s
Explanation:
maximum height, H = 19.7 m
Angle of projection, θ = 15 degree
Let u be the projectile launch speed
Use the formula of maximum height


u = 75.9199 = 76 m /s