Answer:
Question #1- Scientists agree to a standard way of reporting measured quantities in which the number of reported digits reflects the precision in the measurement- more digits, more precision; less digits, less precision. You just studied 14 terms!
Question #2- Units are important because without proper measurement and units to express them, we can never express physical laws precisely just from qualitative reasoning. Units are incredibly important to physics. Two of the most important reasons are the following: (1) they help us. to avoid making mistakes in computation, and (2) they serve as a check on computations once they are completed. In the first case, you can avoid adding 3m and 25cm and coming up with the wrong answer.
Explanation: Hope this helps please mark brainliest!
Answer:
(a) 89 m/s
(b) 11000 N
Explanation:
Note that answers are given to 2 significant figures which is what we have in the values in the question.
(a) Speed is given by the ratio of distance to time. In the question, the time given was the time it took the pulse to travel the length of the cable twice. Thus, the distance travelled is twice the length of the cable.
(b) The tension, 
, is given by
where 
is the speed, is the tension and 
is the mass per unit length.
Hence,
To determine , we need to know the mass of the cable. We use the density formula:
where 
is the mass and 
is the volume.
If the length is denoted by 
, then
The density of steel = 8050 kg/m3
The cable is approximately a cylinder with diameter 1.5 cm and length or height of 620 m. Its volume is
1). I started up my car. Gasoline was spritzed into the cylinders, mixed with air, and then exploded with an electrical spark. As the gasoline vapor instantly burned in the air, several new things were formed that weren't there before, like carbon dioxide, carbon monoxide, water, and oxides of nitrogen.
2). I left my dinner on the stove a little too long, and it got a layer of crunchy crackly sooty carbon on the bottom. That part of it didn't taste too good. This isn't exactly something that happens every day, but more often than I'd like it too.
3). All day, every day, and all night, every night, about 10 or 20 times every minute, I pull air into my lungs. I keep it there for a while, then I blow it out and pull in some fresh stuff. The air I blow out has less oxygen and more carbon dioxide in it than it had when I pulled it in. That's because of the hundreds of chemical reactions going on inside my body, to keep me alive and functioning. I hope these keep going on for many many more days in the future.
Answer:
What is a Pure Substance?
Explanation:
It is something which cannot be divided into parts by physical means, as it's all made up of the same thing. Pure substances are either elements or compounds. Elements can NOT be separated into other types of matter (physically or chemically).
It is called polarizability. A dipole moment is needed for the molecule or atom due to the distortion of the electron cloud. A dipole is a pair of electrical charges that have opposite signs and during a dipole moment two charges separate.
