Answer:
(a) 
(b) 
Explanation:
(a) We use Newton's law of universal gravitation, in order to calculate the gravitational force between electron and proton:
Where G is the Cavendish gravitational constant, 
and 
are the masses of the electron and the proton respectively and r is the distance between them:
The minus sing indicates that the force is repulsive. Thus, its magnitude is:
(b) We use Coulomb's law, in order to calculate the electric force between electron and proton, here k is the Coulomb constant and e is the elementary charge:
Its magnitude is:
The unit 'mb' means millibar which is equivalent to 1/1000 of 1 bar. To convert the units from bar to atmospheres (atm) and to inches Hg (inHg), we need to know the conversion factors.
a.) 1 atm = 1.01325 bar
0.92 mb(1 bar/1000 mbar)(1 atm/1.01325 bar) =<em> 9.08×10⁻⁴ atm</em>
b.) 1 bar = 29.53 inHg
0.92 mb(1 bar/1000 mbar)(29.53 inHg/1 bar) =<em> 0.027 inHg</em>
Answer:
40N
Explanation:
Using the newton's second law of motion
\sum Fx = max
Fm - Ff = max
Fm is the applied force
Ff is the frictional force
m is the mas of the cupboard
ax is the acceleration
Since the speed from the lorry is steady, ax = 0m/s^2
Also Ff = 40N
Substitute into the formula;
Fm - 40 = m(0)
Fm - 40 = 0
Add 40 to both sides
Fm - 40 + 40 = 0 + 40
Fm = 40N
Hence the force with which the man applied to push is 40N
I believe the correct answer from the choices listed above is the second option. With this information, he was able to conclude that the beam was negatively charged. His cathode ray<span> tube experiments led to a very important scientific discovery, the electron. Hope this answers the question.</span>
