Answer:
"we both attract each other with the same force but we know that attraction between two bodies depends upon their mass, greater the mass of two bodies is the force of attraction between them"(got this off the internet).
Answer:
D) negative, due to extra electrons.
Explanation:
The charge that would be gained will be negative charges due to extra electrons.
Electrons are usually lost or gained by bodies that comes in contact with one another.
They occupy the orbital space in an atom and are not strongly held by forces within the atom.
Protons cannot be lost in such manner. They occupy the nucleus and are bounded by strong chemical forces within it.
The polythene and rods are both made up of chemical substances whose units called atoms are made up of subatomic particles of protons, neutrons and electrons. As with all kinds of matter, there would be pool of free electrons round them that can easily be rubbed off due to the weak attractive forces binding them in the atomic sphere.
When the polythene and rods are rubbed, there would be a loss of electrons and the gaining body, polythene becomes negatively charged.
Answer:
-20.0 m/s and 30.0 m/s
Explanation:
Momentum is conserved:
m (30.0) + m (-20.0) = m v₁ + m v₂
30.0 − 20.0 = v₁ + v₂
10.0 = v₁ + v₂
Since the collision is perfectly elastic, energy is also conserved. Since there's no rotational energy or work done by friction, the initial kinetic energy equals the final kinetic energy.
½ m (30.0)² + ½ m (-20.0)² = ½ mv₁² + ½ mv₂²
(30.0)² + (-20.0)² = v₁² + v₂²
1300 = v₁² + v₂²
We now have two equations and two variables. Solve the system of equations using substitution:
1300 = v₁² + (10 − v₁)²
1300 = v₁² + 100 − 20v₁ + v₁²
0 = 2v₁² − 20v₁ − 1200
0 = v₁² − 10v₁ − 600
0 = (v₁ + 20) (v₁ − 30)
v₁ = -20, 30
If v₁ = -20, v₂ = 30.
If v₁ = 30, v₂ = -20.
So either way, the final velocities are -20.0 m/s and 30.0 m/s.
