Answer:
when the reflecting surface is plain and without even small hurdles that are not the visible by our naked eyes. Eg : plain mirror
Explanation:
Answer:
a.3Hz
b.0.0034m
Explanation:
First, we know the flute is an open pipe, because open pipe as both end open and a close organ pipe as only one end close.
The formula relating the length and he frequency is giving as
.
a.we first determine the length of the flute at the fundamental frequency i.e when <em>n</em>=1 and when the speed is in the 342m/s
Hence from
.
since the value of the length will remain constant, we now use the value to determine the frequency when the air becomes hotter and the speed becomes 345m/s.

Hence the require beat is
.
b. since the length is dependent also on the speed and frequency, we determine the new length when she plays with a fundamental frequency when the speed of sound is 345m/s
using the formula
Now to determine the extension,

Answer:
0.67m/s²
Explanation:
Given parameters:
Mass of toy = 1.2kg
Force applied = 0.8N
Unknown:
Acceleration = ?
Solution:
According to newton's second law of motion;
Force = mass x acceleration
Now,
Acceleration =
Acceleration =
= 0.67m/s²
Answer:
5 hours
Explanation:
Let the required time be x hours. The time will be the same for both cars.
The cars will cover different distances because they are travelling at different speeds.
<em>D=S×T
</em>
The distance travelled by the slower car = 50×x miles.
The distance travelled by the faster car = 58×x miles.
The two distances differ by 40 miles.
58x−50x=40
8x=40
x=5 hours
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A second method:
The difference in the distances is 40 miles
The difference in the speeds is #8mph.
The time to make up the 40 miles=
=5 hours
Answer:

Explanation:
= Avogadro's number = 
e = Charge of electron = 
k = Coulomb constant = 
Z = Atomic number of water = 18
M = Molar mass of water = 0.018 kg/mol
m = Mass of person
The charge is given by

Total number of protons and electrons in each sphere




Electrical force is given by

The electrostatic force of attraction between them is 