The culture that gave the visiting Europeans eyeglasses and silk fabric was the Chinese civilization. The Chinese invented eyeglasses over a 1,000 years ago<span>, according to British scientist and historian Sir Joseph Needman. By the time Marco Polo arrived in China around 1270, eyeglasses (which he mentions in his accounts) were widely used in Chinese upper class. On the other hand, s</span>ilk has been used by the Chinese for approximately 5,000 years.<span> The earliest evidence of silk dates back to around 4,000-3,000 BC in Shanxi province, where a culture silk cocoon was found.</span>
Answer:
an artificial body placed in orbit around the earth or moon or another planet in order to collect information or for communication.
Explanation:
Look it up on google
Answer:
False.
Explanation:
The forces on the car and truck are equal and opposite. The equal forces cause accelerations of the truck and car inversely proportional to their mass. That is, If the Truck A exerts a force FAB on car B, then the car will exert a force FBA on the truck. Therefore,
FBA = −FAB
However, this can be explained by Newton's second law. Let's say the truck has mass M and the car has mass m. If the magnitude of the force that both vehicles experience is F, then the magnitudes of their respective accelerations are:
atruck = F/M
acar = F/m
and combining these we get:
atruck/acar = m/M
So if the mass of the car is a lot less than the mass of the truck, then the acceleration of the truck is much smaller than the acceleration of the car, and if you were to watch the collision, the truck would pretty much seem like it's motion was unaffected, but the car's motion will change quite a bit.
Answer:
<em>v = 381 m/s</em>
Explanation:
<u>Linear Speed</u>
The linear speed of the bullet is calculated by the formula:
Where:
x = Distance traveled
t = Time needed to travel x
We are given the distance the bullet travels x=61 cm = 0.61 m. We need to determine the time the bullet took to make the holes between the two disks.
The formula for the angular speed of a rotating object is:
Where θ is the angular displacement and t is the time. Solving for t:
The angular displacement is θ=14°. Converting to radians:
The angular speed is w=1436 rev/min. Converting to rad/s:
Thus the time is:
t = 0.0016 s
Thus the speed of the bullet is:
v = 381 m/s
Answer:
While the use of the type of transformer in a rectifier depends on the voltage requirement or to meet desired operating conditions, a step-down transformer is used mainly to reduce the voltage. It is used to bring the high AC voltage level to a reasonable value or the desired output voltage.
Explanation:
Hope it helps
Correct me if Im wrong
