Answer:
1) joule
2) 
3) 
Explanation:
1) Luminosity is the <u>amount of light emitted</u> (measured in Joule) by an object in a unit of<u> time</u> (measured in seconds). Hence in SI units luminosity is expressed as joules per second (
), which is equal to Watts (
).
This amount of light emitted is also called radiated electromagnetic power, and when this is measured in relation with time, the result is also called radiant power emitted by a light-emitting object.
Therefore, if we want to calculate luminosity the Joule as a unit will be used.
2) Work
is expressed as force
multiplied by the distane
:
Where force has units of
and distance units of
.
If we input the units we will have:
This is 1Joule (
) in the SI system, which is also equal to 
3) The formula to calculate the percent error is:

Where:
is the experimental value
is the accepted value

This is the percent error
Answer:
4 N
Explanation:
mass = 2 kg
acceleration = 2 m/s^2
Force = mass * acceleration
= 2 *2
= 4 N
To solve this problem we will apply the concepts related to the final volume of a body after undergoing a thermal expansion. To determine the temperature, we will use the given relationship as well as the theoretical value of the volumetric coefficient of thermal expansion of copper. This is, for example to the initial volume defined as
, the relation with the final volume as



Initial temperature = 
Let T be the temperature after expanding by the formula of volume expansion
we have,

Where
is the volume coefficient of copper 




Therefore the temperature is 53.06°C
I believe it’s the mass of the box but I don’t no if I’m right
Hope this helped