A12.65 g sample of a radioactive substance is allowed to decay for 17.22 min. at that time, the sample weighed 3.115 g. what is the half-life for this substance?

The speed of light in a material is 0.50 c. what is the critical angle of a light ray at the interface between the material and a vacuum?

Question 1 (5 pts): what is the maximum distance for which you can you resolve the two individual headlights of an on-coming truck as two separate lights rather than one if the headlights are separated by 2.00 m and your eye has a diameter of 1.00 centimeter? assume a wavelength of 500 nm.

Mechanical energy is when the amount of kinetic and potential energies added together remains the same. conserved created lost