Answer: To find the atomic mass of an atom of an element, add up the mass of protons and neutrons.
Explanation: Find the atomic mass of an isotope of carbon that has 7 neutrons. You can see from the periodic table that carbon has an atomic number of 6, which is its number of protons.
Answer:

Explanation:
Index of refraction:
where
is the refractive index,
is the speed of light in vacuum and
is the speed of light in medium.
The speed of light in vacuum is 
Speed of light in medium is 
Thus,

Index of refraction of this substance through yellow light is 
Answer:
8 km/h²
Explanation:
a = v-u/t
v is final velocity, u is initial velocity
a = 40-0/5
a = 8.0 km/h²
Answer:
Explanation:
Given
First bicycle travels 6.10 km due to east in 0.21 h
Suppose its position vector is 

After that it travels 11.30 km at
east of north in 0.560 h
suppose its position vector is 

after that he finally travel 6.10 km due to east in 0.21 h
suppose its position vector is 

so position of final position is given by



t=0.21+0.56+0.21=0.98 h


For direction

w.r.t to x axis
Can be absorbed and transformed into heat. i know this because i used to work as a constructor for lights and i had to go over a training on this subject.