Period = 2 seconds.

frequency = 1/2 cycle/second = 1/2 Hz

If it falls twice every four seconds, then it falls once every two seconds, therefore one falling period is two seconds.

Hz is equal to cycles per second. So if it goes through one cycle per two seconds, then it goes through 1/2 cycle per one second.

Hope this helps!

<span>The first three steps in scientific inquiry are related in that they are all equivalent to being on a fact finding mission. The three steps are to find or develop the question that must be answered, to study all related academic literature on the subject, and then to make a guess as to what the answer is.

I hoped I helped!</span>

**Answer:**

Attractive Property – Magnet

**Explanation:**

attracts ferromagnetic materials like iron, cobalt, and nickel. Repulsive Properties – Like magnetic poles repel each other and unlike magnetic poles attract each other. Directive Property – A freely suspended magnet always points in a north-south direction.

**Answer:**

a) -2.1731 m⁻s

**Explanation:**

**L= length of thread, H= height of ball from ceiling,**

**N/B h= l cosФ, Ф=31°, l=2.7m, g=9.8m⁻s, m= 6kg**

**Required to find speed v, of the ball in m⁻s**

**ω=√g/h, =√g/lcosФ**

**⇒ ω=√9.8/2.7×cos31° **

**= 1.992rad⁻s**

**Now, speed in m/s, v= r.ω**

**where tanФ= r/h ⇒ **

**r= h×cos 31°**

**r= 2.7 × cos(31) × tan(31) =-1.0909m**

**v= 1.992× -1.0909 = -2.1731 m/s**

It is HCO3 the symbol of carbonate