1. the index of refraction for air is approximately 1.00, and for quartz it's about 1.50. a light beam in air strikes the surface of the quartz at an angle of 30° with the normal. when it enters the quartz it is refracted. calculate this approximate angle of refraction.
a. 8 degrees
b. 13 degrees
c. 19 degrees
d. 60 degrees

2. a light beam in air strikes the surface of water at an angle of 26° with the normal. when it enters the water it bends towards the normal and makes an angle of 19° with it. the velocity of light in water is approximately 225,000 km/s. what is the approximate velocity of light in air?
a. 200,000 km/s
b. 300,000 km/s
c. 400,000 km/s
d. 500,000 km/s

    m₁v₁ + m₂v₂ = (m₁ + m₂)vmomentum is conserved.the left-hand side of the equation represents the momentum in the system before the collision.the right-hand side represents the momentum in the system after the collisionm₁ and v₁ represents the mass and the velocity of the physics blockm₂ and v₂ represents the mass and velocity of the ball of puttyv represents the final velocity of the combined mass.the question states the two masses stick together. they combined mass has its own velocity with the body mass the sum of the two objects' massestheir combined momentum is (m₁ + m₂)vto find the magitude of (m₁ + m₂)v, we need to add the vectors on the left-hand side of the equation: m₁v₁ + m₂v₂.note the diagram. i have positioned the vectors in accordance with their directions.the magnitude of the resultant can be calculated using the pythagorean theorem since this is a right triangle situation (north and west are perpendicular)|(m₁ + m₂)v| =  √[ (m₁v₁)² + (m₂v₂)² ]|(m₁ + m₂)v| =  √[ (1.5kg·8.0m/s)² + (0.40kg·20m/s)² ]|(m₁ + m₂)v| =  14.4 kg m/sfor two significant figures (assuming that 20m/s is two), this rounds to 14 kg m/s