Answer:
The final velocity of the thrower is
and the final velocity of the catcher is
.
Explanation:
Given:
The mass of the thrower,
.
The mass of the catcher,
.
The mass of the ball,
.
Initial velocity of the thrower, 
Final velocity of the ball, 
Initial velocity of the catcher, 
Consider that the final velocity of the thrower is
. From the conservation of momentum,

Consider that the final velocity of the catcher is
. From the conservation of momentum,

Thus, the final velocity of thrower is
and that for the catcher is
.
Answer:
a. 2143 turns/m
b. 111.5 m
Explanation:
a. The minimum number of turns per unit length (N/L) can be found using the following equation:


Hence, the minimum number of turns per unit length is 2143 turns/m.
b. The total length of wire is the following:

Since each turn has length 2πr of wire, the total length is:

Therefore, the total length of wire required is 111.5 m.
I hope it helps you!
Answer:
(1) An object that’s negatively charged has more electrons than protons.
(2) An object that’s positively charged has fewer electrons than protons.
(3) An object that’s not charged has the same number of electrons than protons.
Explanation :
Objects have three subatomic particles that are Electrons, protons, and neutrons.
Protons and neutrons are found in the nucleus and electrons rotate or move outside the nucleus. Naturally, protons are positively charged, neutrons have no charge, and electrons are negatively charged.
Therefore, an object that is negatively charged has more electrons than protons. An object that is not charged has the same number of electrons than protons. An object that is positively charged has fewer electrons than protons.
Answer:
Mass of the aluminium chunk = 278.51 g
Explanation:
For an isolated system as given the energy lost and gains in the system will be zero therefore sum of all transfer of energy will be zero,as the temperature will also remain same
A specific heat formula is given as
Energy Change = Mass of liquid x Specific Heat Capacity x Change in temperature
Q = m×c×ΔT
Heat gain by aluminium + heat lost by copper = 0 (1)
For Aluminium:
Q = 
Q = m x 17.94 joule
For Copper:

Q= 4996.53 Joule
from eq 1
m x 17.94 = 4996.53

Mass of the aluminium chunk = 278.51 g