An 'alpha particle' is the same thing as the nucleus of a helium atom ...
a little bundle made of 2 protons and 2 neutrons.
A 'beta' particle is an electron.
The mass of an alpha particle is more than 7,000 times the mass of
an electron, so it certainly takes more energy to get it moving.
The things that determine the amount of an object's gravitational potential energy are ...
-- mass of the object
-- gravitational acceleration in the place where the object is
-- height of the object above the ground or the floor
A). <em>a slice of bread; </em> No. It's still a slice of bread even if it's on the ground.
B. <em>A compressed spring; </em> No. It's still a compressed spring even if it's on the ground.
C. <em>An apple on a tree</em>; <em>Yes !</em> It can't be an apple on a tree if it's on the ground.
D. <em>A stretched bow string</em>; <em>No.</em> It's still a stretched bowstring even if it's on the ground.
Answer:
Explanation:
Let's use the decay equation.
Where:
- A is the activity at t time
- A₀ is the initial activity
- λ is the decay constant
We know that 
So we have:
Therefore, the half-life of the source is 6 hours.
I hope it helps you!
The rod transferred negatively charged particle to the metal sphere. The rod becomes less negatively charged than it was originally (originally it was charged to -21 nc, now it has -8, and -8>-21), so it must have moved 13 nc of negative charge to the sphere.
Answer:
critical angle is the angle of incidence in optically denser medium, for which the angle of reflection in the less denser medium is 90 degree
Explanation:
total internal reflection occurs at one particular angle of incidence where the reflected ray lies on the boundary.
this angle is called the critical angle
