The work done to pull the sister back on the swing is equal to the increase in potential energy of the sister:

(1)
where m is the sister's mass, g is the gravitational acceleration and

is the increase in altitude of the sister with respect to its initial position.
By calling

the angle of the chain with respect to the vertical, the increase in altitude is given by

(2)
where L is the length of the chain.
Putting (2) inside (1), we find

from which we can find the mass of the sister:
Answer:
D: The distance between the particles decreases
Explanation:
Taking away energy slows down molecules, like how you slow down when you are cold (I think)
2 is the answer have a nice day <3
Answer: The common difference between surface EMG and intramuscular EMG is that that former is non-invasive while the later is an invasive method
Explanation:
Electromyography (EMG) is used clinically for the examination of muscle excitations (muscle electrical activity) in both normal or abnormal conditions. There are two forms of EMG includes:
--> Surface EMT and
--> Intramuscular EMT
Surface EMT is a non invasive method of examination of muscle excitations for superficial and easily accessible muscles.
Intramuscular EMT is the invasive method of examination of muscle excitations usually for deep muscles.
The difference between the two forms of EMT includes:
- surface EMT is non- invasive while intramuscular EMT is invasive
- surface EMT is used to access superficial muscle while intramuscular EMT is used to access deep muscles.
- surface EMT requires less skill and time to carry out while intramuscular EMT requires special skills and takes more time while carrying out the procedure.