Answer:
mass is the amount of "matter" in an object. weight is the force exerted on an object by gravity
Explanation:
Circuit breaker is a device that is designed to open an overloaded circuit and prevent overheating. The correct option in regards to the given question is option "a". The main purpose of the circuit breaker is to disconnect the defective switch from the circuit as soon as any problem arises. This helps in preventing any kind of major accident. Overheating can result in a big accident and the circuit breaker is the device that senses the overheating and disconnects the switch before any major incident. It is an automated system that acts as a protective devise.
Meter and second is the correct answer.
Answer: 
Explanation:
For this exercise you can use the Pythagorean theorem to find the magnitude of the resultant displacement.
Then:

You can observe that the square of the displacement is equal to the sum of the square of the horizontal displacement and the square of the vertical displacement.
Since the pirate walks 37.0 meters north and then turns and walks 8.5 meters east:

Substituting values and solving for "d", you get:

In the photoelectric effect, the energy given by the incoming photon is used partially to extract the electron from the metal (work function) and the rest is converted into kinetic energy of the electron:

where
hf is the energy of the photon, with h being the Planck constant and f the frequency of the photon

is the work function
K is the kinetic energy of the electron
When K=0, we have the minimum energy required to extract the electron from the metal, so the equation becomes

(1)
If we convert the work function of gold into Joules:

We can re-arrange eq.(1) to find the minimum energy of the photon: