Answer:
When <em>a scientist on Earth drops a hammer and a feather at the same time an astronaut on the moon drops a hammer and a feather, the result</em> expected is that <em>the hammer hits the ground before the feather on Earth, and the hammer and feather hit at the same time on the moon (option D).</em>
Explanation:
In the abscence of atmosphere (vacuum), the objects fall in free fall. This is, the only force acting on the objects is the gravitational pull, which is directed vertlcally downward.
Under such absecence of air, the equations that rules the motion are:
- V = Vo + gt
- d = Vo + gt² / 2
- Vf² = Vo² + 2gd
As you see, all those equations are independent of the mass and shape of the object. This explains why <em>when an astronaut on the moon drops a hammer and a feather at the same time</em>, <em>the hammer and feather hit at the same time on the moon</em>, a space body where the gravitational attraction is so small (approximately 1/6 of the gravitational acceleration on Earth) that does not retain atmosphere.
On the other hand, the air (atmosphere) present in Earth will exert a considerable drag force on the feather (given its shape and small mass), slowing it down, whereas, the effect of the air on the hammer is almost neglectable. In general and as an approximation, the motion of the heavy bodies that fall near the surface is ruled by the free fall equations shown above, so, <em>the result </em>that is<em> expected when a scientist on Earth drops a hammer and a feather at the same time is that the hammer hits the ground before the feather</em>.
Answer:
121 K
Explanation:
Step 1: Given data
- Initial volume (V₁): 79.5 mL
- Initial temperature (T₁): -1.4°C
- Final volume (V₂): 35.3 mL
Step 2: Convert "-1.4°C" to Kelvin
We will use the following expression.
K = °C + 273.15 = -1.4°C + 273.15 = 271.8 K
Step 3: Calculate the final temperature of the gas (T₂)
Assuming ideal behavior and constant pressure, we can calculate the final temperature of the gas using Charles' law.
V₁/T₁ = V₂/T₂
T₂ = V₂ × T₁/V₁
T₂ = 35.3 mL × 271.8 K/79.5 mL = 121 K
There are types of lens; concave and convex lens.
The concave lens is a lens which has an inward curve in the middle, that is, the edges of the curve are thicker than the center of the lens, because of this, any light that enter the lens will spread out [diverge]. An image will look smaller and upright when viewed by a concave lens. Image formed by concave lens are usually VIRTUAL.
A concave lens will produce a real image ONLY if the object is located beyond the focal point of the lens.
A convex lens is a converging lens, this is because, the center of the lens is thicker than its edges. Any ray of light that passes through the lens will converge at the middle of the lens at point called principal focus. A convex lens produce a VIRTUAL image when the object is placed infront of the focal point. The virtual image formed is always magnified and upright.<span />
Hey there:
Correct answer is :
(b) NaNH₂
Sodium azanide NaNH₂ is the conjugate base of ammonia NH₃
Correct answer is :
(b) NaNH₂
I hope this will help !
