Answer:
The frequency of the sound wave is 800Hz
The speed of sound in a is about 340m/s.
Velocity = frequency x wavelength
making wavelength the subject formula
wavelength = Velocity/frequency.
wavelength = 340/800
wavelength = 0.425m.
Answer:

cubic metre or 1e-9
Explanation:
•By division. Number of cubic millimetre divided(/) by 1000000000, equal(=): Number of cubic metre.
•By multiplication. 83 mm3(s) * 1.0E-9 = 8.3E-8 m3(s)
Here we have mass that moves at ceratin speed. This means that we have momentum. The law that must be observed is law of conservation of momentum. It states that momentum before certain event is equal to a momentum after that event. Here we have three masses so we can write this as:

Before the firecracker blows a coconut does not move, so left side is equal to 0:

We know that m1=m2=m and m3=2m. Also we are asked to find v3f so we can rewrite formula:

We must take in consideration that two parts with same mass do not move in same direction. The center of mass of these two parts moves between them at angle of 45° with respect to both south and west. The speed of a center of mass is:

This speed we can insert into formula for v3f:

We can see that part of a coconut with biggest mass has same speed as center of mass of two other parts. Negative sign shows that direction is opposite to direction of two pats. Biggest part moves towards north-east.
Answer:
The wire now has less (the half resistance) than before.
Explanation:
The resistance in a wire is calculated as:

Were:
R is resistance
is the resistance coefficient
l is the length of the material
s is the area of the transversal wire, in the case of wire will be circular area (
).
So if the lenght and radius are doubled, the equation goes as follows:

So finally because the circular area is a square function, the resulting equation is half of the one before.
Ahhh... hello! I’ve done a science experiment that has asked this sort of question. Not as easy as it sounds... I know. I’ll tell you what I learned from that experiment. The answer will depend on the materials the ball is made of and then also your drop length. After these two things are determined, you can get a pretty close time and measurement. I hope this information helps. Have a great night!
~Brooke❤️