Answer:
Protons and neutrons are heavy, Electrons are extremely light
Explanation:
Protons and neutrons are heavier than electrons and reside in the nucleus at the center of the atom. Electrons are extremely lightweight and exist in a cloud orbiting the nucleus.
Answer:
563712.04903 Pa
Explanation:
m = Mass of material = 3.3 kg
r = Radius of sphere = 1.25 m
v = Volume of balloon = 
M = Molar mass of helium = 
= Density of surrounding air = 
R = Gas constant = 8.314 J/mol K
T = Temperature = 345 K
Weight of balloon + Weight of helium = Weight of air displaced

Mass of helium is 6.4356 kg
Moles of helium

Ideal gas law

The absolute pressure of the Helium gas is 563712.04903 Pa
(a) This is a freefall problem in disguise - when the ball returns to its original position, it will be going at the same speed but in the opposite direction. So the ball's final velocity is the negative of its initial velocity.
Recall that

We have
, so that

(b) The speed of the ball at the start and at the end of the roll are the same 8 m/s, so the average speed is also 8 m/s.
(c) The ball's average velocity is 0. Average velocity is given by
, and we know that
.
(d) The position of the ball
at time
is given by

Take the starting position to be the origin,
. Then after 6 seconds,

so the ball is 42 m away from where it started.
We're not asked to say in which direction it's moving at this point, but just out of curiosity we can determine that too:

Since the velocity is positive, the ball is still moving up the incline.
Explanation:
We have,
Length of a metal rod is 55 cm or 0.55 m
Change in length is 0.2 cm or 0.002 m
It is required to find the change in temperature of a metal rod. The coefficient of linear expansion is given by :

is the change in temperature

So, the change in temperature is 303.03 degrees Celsius.