To determine the period of a wave you need not utilize the value for the wave speed.
The formula for the period is T= 1/f
T stands for period/time while f is for frequency. Substitute the value for the frequency which is 60 Hz. That would give you:
T= 1/60 Hz
convert Hz to cycles per second to extract the unit of time (s).
60 Hz x 1/s/1 Hz= 60/s
To continue the computation:
T=1/60/s that will give you a T= 0.017 s or 17 ms.
Answer:
The final velocity of 18 kg ball is 
= 42.09 
Explanation:
Mass of first ball 
= 18 kg
Mass of second ball 
= 47 kg
Initial velocity of 18 kg ball 
= 76
Initial velocity of 47 kg ball = 0
Final velocity of 18 kg ball = ??
Final velocity of 18 kg ball is given by the formula
= 
Put all the values in above formula we get
= 2 × 18 × 
= 42.09
Thus, the final velocity of 18 kg ball is = 42.09
The correct answer is A. Most reactive non metals.
Firstly if some one knows how to read the periodic table he would have no confusion in deciding whether group 7 has metals or non metals. Group 7 contains non metals so basically we can easily cancel out two options of metals.
Secondly group 7 non metals are the most reactive non metals as they need only one electron in order to complete their valence shell and become stable.
A fire because you feed it wood, it lives longer but if you give it a drink, water, then it dies.
