Answer:
in the direction of motion of Jacob
Explanation:
Given:
mass of Jacob, 
velocity of Jacob, 
mass of Ethan, 
velocity of Ethan, 
Now using the conservation of linear momentum for the case:
(When the two masses in motion combine to form one after the collision then they will move together in the direction of the greater momentum.)


in the direction of motion of Jacob as it was assumed to be positive.
Answer:
θ = 45º
Explanation:
The light that falls on the second polarized is polarized, therefore it is governed by the law of Maluz
I = I₀ cos² θ
in the problem they ask us
I = ½ I₀
let's look for the angles
½ I₀ = I₀ cos² θ
cos θ = √ ½ = 0.707
θ = cos 0.707
θ = 45º