Calculate the kinetic energy in units of electron volts for an electron emitted from a surface with a work function of 1.5 ev that has been illuminated with632.8-nm (red) helium neon laser, such as those used in a supermarket scanner. perform the same calculation for a 543.5-nm (green) helium-neon laser.

The kinetic energies are 0.46 eV and 0.78 eV.

Explanation:

Given that,

Work function = 1.5 eV

Wavelength = 632.8 nm

We need to calculate the energy for red helium neon laser

Using formula of energy

Put the value into the formula

We need to calculate the kinetic energy

Using formula of K.E

=work function

E = energy

Put the value into the formula

We need to calculate the energy for green helium neon laser

Using formula of energy

We need to calculate the kinetic energy

Using formula of K.E

Hence, The kinetic energies are 0.46 eV and 0.78 eV.

given data:

determine the horse power (h.p) = ?

force applied to move the box(f) = 10 pounds,

box lifted from a distance         (d) = 3 feet

time taken to lift                         (t) = 10 sec,

the horse power is defined as amount of work required to move a load. the horse power is equal to 550 foot-pound per second

                  1 h.p   = 550 foot-pound/second

it can also be defined as the the load that need to be move a body for certain distance in a certain amount of time.

mathematically,

                      h.p = (force × distance)/ time

                            = (10 × 3)/ 10

                            = 30/10

                            = 3 foot -pound/sec

hence, the horse power is needed to move the box is 3 foot-pound/second

important note: 1 h.p = 550 foot-pound/second = 746 watts

f is prop to m1xm2 double m1 double force