The first spring has the stiffness -> 10 N/cm the second has the stiffness-> 2 N/cm

They're now put together that they are one whole spring.

calculate the spring stiffness of the newly created spring

Two polarizers are oriented at 40∘ to each other and plane-polarized light is incident on them. if only 16 percent of the light gets through both of them, what was the initial polarization direction of the incident light?

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

What are the similarities & differences between a thermistor and a light dependent resistor in physics?