Determine the amount of energy carried in 2.0 m of a 4.6-mW He-Ne laser beam if the cross-sectional area of the beam is 4.1 × 10−⁶ m². A)1.4E-10 J B)4.9E-12 J C)3.1E-11 J D)6.1E-8 J E)1.0E-11 J

Question

Quizplus · Accepted Answer

The energy carried by a laser beam is given by the formula:

E = P × t

where P is the power of the beam and t is the time for which the beam is present. In this case, we are given the power of the beam as 4.6 mW and the length of the beam as 2.0 m. We need to find the energy carried by the beam, which can be calculated as:

E = P × A × t

where A is the cross-sectional area of the beam. Substituting the given values, we get:

E = 4.6 × 10^-3 × 4.1 × 10^-16 × 2

E = 3.1 × 10^-11 J

Therefore, the energy carried by the laser beam is 3.1 × 10^-11 J, which corresponds to choice C.

Determine the Amount of Energy Carried in 2