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:
Acoustic microstreaming
Explanation:
Acoustic microstreaming is the swirling effect produced by water stream confined in a spaced of a periodontal pocket.
- It is the movement of water in a particular direction as a result of mechanical pressure within the fluid body.
- They are often used in dental procedures to remove particulates from the teeth.
- It mostly relies on the properties of sound waves to achieve this goal
Volume= Length X width X height.
Plug in the values for each and solve for the volume.
V= (L)(W)(H)
V=(4cm)(5cm)(10cm).
Answer:
Average force = 3.5 kN
Explanation:
Given:
Mass of Jennifer (m) = 50 kg
Initial velocity = 35 m/s
Time taken to stop body = 0.5 s
Find:
Average force
Computation:
v = u + at
0 = 35 + a(0.5)
Acceleration (a) = - 70 m/s² = 70 m/s²
Average force = ma
Average force = (50(70)
Average force = 3500 N
Average force = 3.5 kN
Answer:
The length of rod A will be <u>greater than </u>the length of rod B
Explanation:
We, know that the formula for final length in linear thermal expansion of a rod is:
L' = L(1 + ∝ΔT)
where,
L' = Final Length
L = Initial Length
∝ = Co-efficient of linear expansion
ΔT = Change in temperature
Since, the rods here have same original length and the temperature difference is same as well. Therefore, the final length will only depend upon the coefficient of linear expansion.
For Rod A:
∝₁ = 12 x 10⁻⁶ °C⁻¹
For Rod B:
∝₂ = β₂/3
where,
β₂ = Coefficient of volumetric expansion for rod B = 24 x 10⁻⁶ °C⁻¹
Therefore,
∝₂ = 24 x 10⁻⁶ °C⁻¹/3
∝₂ = 8 x 10⁻⁶ °C⁻¹
Since,
∝₁ > ∝₂
Therefore,
L₁ > L₂
So, the length of rod A will be <u>greater than </u>the length of rod B
