Answer: i think c
Explanation:QA: “What is ordinary glass made of ?”
Glass is mostly silica, or silicon dioxide, present as quartz in many types of sand. Pure silica forms a highly transparent glass, but has a very high melting or softening temperature, around 1700°C. Even at such high temperatures it is highly viscous and difficult to work. Its use is largely confined to applications requiring high transparency to ultra-violet and infra-red radiation, stability at elevated temperatures or low thermal expansion coefficient.
“Ordinary glass” windows and drinking vessels are typically made from soda-lime glass, containing silica with around 25% sodium, calcium and other oxides, which together reduce the softening temperature to roughly 500–600°C
The best and most correct answer among the choices provided by your question is the second choice or letter B.
<span>When the switch is closed, the current instantaneously becomes 1.</span>
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
Answer:
255 Hz
Explanation:
With 5 beats per second with the 250 Hz fork, we know the unknown fork is either 250 - 5 = 245Hz or 250 + 5 = 255 Hz
With 15 beats per second with the 270 Hz fork, we know the unknown fork is either 270 - 15 = 255Hz or 270 + 15 = 285 Hz (most people would have a hard time discerning 15 beats per second... 5 per second is hard enough)
As 255 is the common frequency, it is the one selected.
What is the weight of a 4.2 kg bowling ball on Mars?
Answer:
1.59 kg
Explanation:
The formula is:
<u>F = G((Mm)/r2)
</u>
F is the gravitational force between two objects,
G is the Gravitational Constant (6.674×10-11 Newtons x meters2 / kilograms2),
M is the planet's mass (kg),
m is your mass (kg), and
r is the distance (m) between the centers of the two masses (the planet's radius).
Hope this helps
--Jay
Answer:
B. 17m/s
Explanation:
This question contains a graph that illustrates the relationship between the speed of a car over time. The graph shows that one can make an inference of the amount of time it takes for the car to cover a particular speed and vice versa.
In this case, after 3 seconds, the speed of the car will be 17 m/s. This inference was got by tracing the position of 3s in the x-axis to the value on the y-axis. Doing this, the best inference for the speed of the car after 3 seconds is 17m/s.
