Hello!
These atoms are isotopes
Isotopes are atoms with the same number of protons (which determine the atomic number) and a different number of neutrons. These two atoms have the same number of protons (13), but a different number of neutrons, so they are isotopes.
According to their number of protons, these are Aluminum isotopes: ²⁷Al (stable), and ²⁶Al (radioactive), respectively.
Have a nice day!
I understand that sound travels faster in water then in air. Water is a liquid, and air is gas.
Water still has the ability to roll the molecules over each other (so water can flow), it has some flexibility.
But I do not understand how a solid that is inflexible can make sound waves travel faster then in a flexible liquid.
In fact, sound waves travel over 17 times faster through steel than through air.
Sound waves travel over four times faster in water than it would in air.
The distance covered by Arthur is
3t
The distance covered by Betty from where Arthur started is
100 - 2t
They meet each other when this distance is equal
3t = 100 - 2t
t = 20 s
Since the dog has a constant speed of 5m/s, the distance that Spot has run is
5 m/s (20s) = 100 m
Answer:
Explanation:
Given that,
Mass of the clock, m = 108 kg
When the clock is not moving, force acting on it, 
For the clock in motion, force acting on it, 
To find,
Solution,
When an object is at rest, the force acting on it is called force due to static friction and if the object is in motion, the force acting on its called force due to kinetic friction.
Let 
is the coefficient of static friction. Force is given by :
Let 
is the coefficient of kinetic friction. Force is given by :
