Answer:
Molecules are made up of atoms that are held together by chemical bonds. These bonds form as a result of the sharing or exchange of electrons among atoms. The atoms of certain elements readily bond with other atoms to form molecules. ... The element helium is a one-atom molecule.
A shopkeeper uses a force of 50N to lift a box to a shelf 1.5m high. How much work is done?
Answer:
, 
Explanation:
The force experienced by the ion due to the magnetic field is given by:

where
q is the charge
v is the speed
B is the intensity of the magnetic field
The cetripetal force is

where
m is the mass
r is the radius of the circle
Since the magnetic force acts as centripetal force, we can equate the two expressions:

Re-arranging it, we find the radius:

Now, if we want to find the time it takes for the ion to make one complete circle (=the period), we just need to divide the length of one circumference by the speed:

And susbstituting the expression we found before for r, we find

Answer:
the red pointer on the magnet ( grey region) : points towards north
red pointer outside the magnet ( white region) is pointing towards south
Explanation:
please see the attached image
<span>conservation of momentum
mass(ball) × speed(ball) = mass(cannon) × speed(cannon)
(8.3 kg) × (187.9 m/s) = (949.3 kg) × v
1.64 m/s = v
</span>