PhysicsLAB: Least Time Activity

Refer to the following information for the next eight questions.

Measure each of the following distances if a beam of light traveled each path.

PA = ____ cm

PB = ____ cm

PC = ____ cm

PD = ____ cm

AS = ____ cm

BS = ____ cm

CS = ____ cm

DS = ____ cm

Refer to the following information for the next four questions.

Time calculations using t = nd/c where c = 3 x 10⁸ m/sec.

time_{PA + AS} = ____ sec

time_{PB + BS} = ____ sec

time_{PC + CS} = ____ sec

time_{PD + DS} = ____ sec

Refer to the following information for the next two questions.

Determine which path (PBS or PCS) requires the least time. If PBS has the least time, construct a normal at B. If PCS has the least time, construct a normal at C. Measure the angles between the top ray (q ₁) and the bottom ray (q ₂) with the normal.

q ₁ = _____

q ₂ = ____

Refer to the following information for the next two questions.

Use Snell's Law (n₁ sin q ₁ = n₂ sin q ₂) calculate an experimental value for the index of the second medium and then give a percent error against the accepted value of 1.5.

experimental n₂= _____

percent error = ____