Objects should be cooled before their mass is determined on a sensitive balance because it could damage the balance. Also, because it would give you wrong reading of the mass. Hot objects would warm the air around it. A warm air would expand and would produce convection as it rises causing to give the object a mass that is less than the actual. Another reason would be it would cause instability in the readings, the mass would fluctuate every now and then due to the convection currents around the object. It is always recommended to weigh the masses of objects that are in room temperature.
It causes or makes a magnetic field.
Oxygen has an atomic number 8, because it has 8 protons and 8 electrons.
The first shell of an atom can hold up to 2 electrons but oxygen has 8 electrons, in that eight electrons 2 are in the first shell, so it has 6 more electrons left. The second shell can hold up to 8 electrons, oxygen has only 6 more electrons after the first shell is full, so it will have 6 electrons in the second shell
From this we know that oxygen has 2 shells so it is in period 2, and by counting from left to right, the sixth box in period 2 lies on group 16
Therefore Oxygen lies on group 16 and period 2
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Answer:
<em>The cyclist is traveling at 130 m/s</em>
Explanation:
<u>Constant Acceleration Motion
</u>
It's a type of motion in which the velocity of an object changes by an equal amount in every equal period of time.
Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, the following relation applies:

The cyclist initially travels at 10 /s and it's accelerating at a=6m/s^2. We need to know the new speed when t= 20 seconds have passed.
Apply the above equation:



The cyclist is traveling at 130 m/s
The deflection angle is 37.29º if the prism was made of polystyrene plastic.
What is a laser beam?
Laser beam is a light beam propagating dominantly in one direction.
It is a beam of radiation produced from a laser.
Here given that,
refraction index of glass, n1= 1.52
refraction index of polystyrene plastic, n2 = 1.59
deflection angle, B = 22.6º
For the second surface,
B = 45º - 22.6º
B = 22.40º
Now from the formula of Snell's law:
n1 sinФ = n2 sin B
sin B / sinФ = n1 / n2
sinФ = (sin 22.40º) * ( 1/ 1.59)
Ф = 37.29º
Hence,
The deflection angle is 37.29º if the prism was made of polystyrene plastic.
Learn more about laser beam here:
<u>brainly.com/question/4218151</u>
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