Answer:
The density is 
Explanation:
From the question we are told that
The weight in air is 
The weight in water is 
The weight in a unknown liquid is 
Now according to Archimedes principle the weight of the object in water is mathematically represented as
Where 
is he mass of the water displaced
substituting value
Now according to Archimedes principle the weight of the object in unknown is mathematically represented as
Where 
is he mass of the unknown liquid displaced
substituting value
dividing equation 2 by equation 1
=> 
Now since the volume of water and liquid displaced are the same then
This because
So if volume is constant
mass = constant * density
Where 
is the density of the liquid
and 
is the density of water which is a constant with a value 
So
-- Light is electromagnetic radiation.
-- Electromagnetic radiation has no mass.
-- Electromagnetic radiation can travel through vacuum.
Answer:
the signs of heat and work are; -Q and -W
Explanation:
The first law of thermodynamics is given by; ΔU = Q − W
where;
ΔU is the change in internal energy of a system,
Q is the net heat transfer (the sum of all heat transfer into and out of the system)
W is the net work done (the sum of all work done on or by the system).
Now, The system in this case is the tire and since the air gets warmer, heat must have left the system. Therefore Q is negative (-Q).
Since work is done by the system, W remains negative.
Thus, the signs of heat and work are; -Q and - W
When you refer to how close a measured value is to a standard, accepted or known value, you are talking about the ACCURACY of the data. This is the definition of accuracy when it comes to engineering and other fields of science.
Accuracy is usually associated or with the term precision, as their definitions are often interchanged.
An object with non-zero mass (even negligible mass is non-zero) will never reach the speed of light. Due to relativistic effects, each "unit" of acceleration becomes less effective at increasing your velocity (relative to some other object, of course) as your relative velocity approaches the speed of light.
And even if there was a way, If you would accelerate to the 99,99% of the speed light in just 1 second, you would experience a G-force of aprox. 30,600,000 g's which is enough to kill you in a few seconds
