Explanation:
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The answer, I believe, is, "B. When particles collide, no energy is lost."
M = 40 Kg , g=9.8 m/s² , h = 2 m
PE = m g h
PE = (40) (9.8) (2)
PE = 784 J
KE = PE
½m v² = m g h
½ v² = g h
½ v² = (9.8) (2)
½ v² = 19.6
v² = 19.6×2
v² = 39.2
V = √39.2
V = 6.26 m/s
KE = ½mv²
KE = ½(40) (6.26)²
KE =783.8 J
The acceleration due to gravity only points downward with magnitude g. The angle of the projectile doesn't matter.
