If 745-nm and 660-nm light passes through two slits 0.54 mm apart, how far apart are the second-order fringes for these two wavelengths on a screen 1.0 m away

0.82 mm

Explanation:

The formula for calculation an bright fringe from the central maxima is given as:

so for the distance of the second-order fringe when wavelength = 745-nm can be calculated as:

where;

n = 2

= 745-nm

D = 1.0 m

d = 0.54 mm

substituting the parameters in the above equation; we have:

= 0.00276 m

= 2.76 × 10 ⁻³ m

The distance of the second order fringe when the wavelength = 660-nm is as follows:

= 1.94 × 10 ⁻³ m

So, the distance apart the two fringe can now be calculated as:

= 2.76 × 10 ⁻³ m - 1.94 × 10 ⁻³ m

= 10 ⁻³ (2.76 - 1.94)

= 10 ⁻³ (0.82)

= 0.82 × 10 ⁻³ m

=  0.82 × 10 ⁻³ m

= 0.82 mm

Thus, the distance apart the second-order fringes for these two wavelengths = 0.82 mm

Your power output as you climb the stairs is 300.92 Watts.

Explanation:

Power is the amount of work per unit of time that some object or system produces. Power is calculated by:

Power is measured in watts (W), equivalent to one joule (J) of work done per second (s).

Work is defined in physics as the force that is applied to a body to move it from one point to another. The work is calculated as the multiplication of the force by the distance:

Work = F*d

Newton's second law says that the acceleration of a body is proportional to the resultant of forces on the acting and inversely proportional to its mass. This is expressed by the equation:

F=m*a

In this case,  

considering that the force of gravity acting on you, the force is:

F=m*a= 72.5 kg * 9.8 =710.5 N

The distance is the multiplication between the number of stairs and the height of the stairs in meters (18 cm= 0.18 m, being 100 cm= 1 m):

d = 40 * 0.18 m= 7.2 m

Then:

Work= 710.5 N* 7.2 m

Work= 5,115.6 J

So finally the power can be calculated as:

P= 300.92 Watts

Your power output as you climb the stairs is 300.92 Watts.