1. Intro to Physics Units

A forward-bias voltage of $15.0$ mV produces a positive current of $9.25$ mA through a $p-n$ junction at $300$ K. What does the positive current become if the forward-bias voltage is reduced to $10.0$ mV?

Calculate the minimum beam energy in a proton-proton collider to initiate the $p+p\to p+p+{\eta }^0$ reaction. The rest energy of the ${\eta }^0$ is $547.3$ MeV (see Table $44.3$).

A particle has rest mass $6.64\times {10}^{-27}$ kg and momentum $2.10\times {10}^{-18}$ kgm/s.

(a) What is the total energy (kinetic plus rest energy) of the particle?

(b) What is the kinetic energy of the particle?

(c) What is the ratio of the kinetic energy to the rest energy of the particle?

The atomic mass of $14C$ is $14.003242$ u. Show that the ${\beta }^{-}$ decay of $14C$ is energetically possible, and calculate the energy released in the decay.

The earth's circumference is approximately 40.1 Mm (megameters). What is this circumference in kilometers?

Astronomers often detect radio waves with wavelengths of 3,000,000,000 nm. What is this wavelength expressed in decameters (dam)?

Rewrite 0.00016 kg in scientific notation.

Rewrite 299,800,000 m/s in scientific notation.

Rewrite 3.41 × 10⁻⁴ in standard form:

Rewrite 9.98 × 10⁷  in standard form.

The position of an object is given by 𝓍 = At + Bt², where 𝓍 is in meters and t is in seconds. What are the units of A and B?

Write the following numbers in powers of 10 notation: 0.219.

Write out the following numbers in full with the correct number of zeros: 2.5 x 10⁻¹