<h3><u>Answer;</u></h3>
<em>Electrons </em>
<h3><u>Explanation;</u></h3>
- <em><u>Thomson contributed to the model of an atom by discovery of </u></em><em><u>electrons </u></em><em><u>and thus proving the existence of sub-atomic particles in an atom. </u></em>
- <u><em>Thomson used cathode ray tube, and demonstrated that cathode rays were negatively charged.</em></u> According to his model normally known as the plum pudding in which he stated that an atom is composed of electrons as subatomic particles that are surrounded by positive charges to balance the electrons.
Answer: 810 J
Explanation: work W = F·s = 101 N · 8.0 m = 808 J
Force F = u mg = 101 N in which u is friction constant. Also mass is included in force.
The force of gravity on a certain object is calculated through the equation,
F = Gm1m2 / r²
where F is the force, G is a constant, m1 and m2 are masses of the object and Earth, respectively and r is the distance. Substituting the known values for this item,
F = (6.67 x 10⁻¹¹ N.m²/kg²)(1 kg)(5.98 x 10²⁴ kg)/ (6.4 x 10⁶ m)²
F = 9.37 N
Answer: 9.37 N
