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:
10.4 m/s
Explanation:
The problem can be solved by using the following SUVAT equation:
where
v is the final velocity
u is the initial velocity
a is the acceleration
t is the time
For the diver in the problem, we have:
is the initial velocity (positive because it is upward)
is the acceleration of gravity (negative because it is downward)
By substituting t = 1.7 s, we find the velocity when the diver reaches the water:
And the negative sign means that the direction is downward: so, the speed is 10.4 m/s.
As the container starts to heat up, so will the neon gas. Heat is nothing but energy, and when you add energy to a gas, it will start vibrating much faster and hit the edges of the container at a higher rate and a faster velocity. Therefore, it's possible to deduce that the container will most likely rupture and/or "explode".
Answer:
ωB = 300 rad/s
ωC = 600 rad/s
Explanation:
The linear velocity of the belt is the same at pulley A as it is at pulley D.
vA = vD
ωA rA = ωD rD
ωD = (rA / rD) ωA
Pulley B has the same angular velocity as pulley D.
ωB = ωD
The linear velocity of the belt is the same at pulley B as it is at pulley C.
vB = vC
ωB rB = ωC rC
ωC = (rB / rC) ωB
Given:
ω₀A = 40 rad/s
αA = 20 rad/s²
t = 3 s
Find: ωA
ω = αt + ω₀
ωA = (20 rad/s²) (3 s) + 40 rad/s
ωA = 100 rad/s
ωD = (rA / rD) ωA = (75 mm / 25 mm) (100 rad/s) = 300 rad/s
ωB = ωD = 300 rad/s
ωC = (rB / rC) ωB = (100 mm / 50 mm) (300 rad/s) = 600 rad/s
Possible Solutions to the Problem of Global Energy Crisis:
1. Move Towards Renewable Resources.
2. Buy Energy-Efficient Products.
