A) no H30+ ions or OH- ions.
The work done by Joe is 0 J.
<u>Explanation</u>:
When a force is applied to an object, there will be a movement because of the applied force to a certain distance. This transfer of energy when a force is applied to an object that tends to move the object is known as work done.
The energy is transferred from one state to another and the stored energy is equal to the work done.
W = F . D
where F represents the force in newton,
D represents the distance or displacement of an object.
Force = 0 N, D = 20 cm = 0.20 m
W = 0
0.20 = 0 J.
Hence the work done by Joe is 0 J.
Answer:


Explanation:

Required
The units of A and B
From the question, we understand that:

This implies that each of
and
will have the same unit as 
So, we have:


The unit of t is (s); So, the expression becomes

Divide both sides by 


Answer:
(a)0.0002778
(b)
Explanation:
(a) The minute hand has a period of 60 minutes ( or 60 * 60 = 3600 seconds) for 1 circle. Its frequency per second would be
1 / 3600 = 0.0002778
(b) The hour hand has a period of 24 hours ( or 24*60 * 60 = 86400
seconds) for 1 circle. Its frequency per second would be
