Momentum can be conserved in two-dimensional collisions, but kinetic energy is only conserved in some one dimensional collisions. a.True b. False because kinetic energy can be conserved in 2-d collisionsc. False because momentum is only conserved when all three dimensions are includedd. False because kinetic energy can only be conserved if all three dimensions are included

b.False because kinetic energy can be conserved in 2-d collisions

Explanation:

Momentum is always conserved in 2-d collisions. You have to consider each dimension.

before ∑m*Vx = ∑m*Vx after

before ∑m*Vy = ∑m*Vy after

In elastic collision kinetic energy is also conserved in in 2-d collisions.

before ∑ 1/2*m*V² = ∑ 1/2*m*V² after

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray