Answer:
a.)How far from the building does the ball hit the ground?
72 m
b.)How long does it take to hit the ground?
6 s
c.)What is its speed when it hits the ground?
63.48 m/s
Explanation:
When an object is in free fall with no air resistance present or wind acting on it it only is under the influence of gravity. Gravity acts straight down and accelerates the object all the way to the ground. If there is air resistance or a wind force on the object it will have an acceleration that isn't 9.8 m/s^2
Answer:
the amount of heat that gets through both the wires will be same.
Explanation:
By the Fourier's law of conduction we have:
where:
= rate of heat transfer
k = thermal conductivity of the material
A = area of the material
dT = temperature difference across the length dx
According to the question, the system to be analysed is isolated from the surrounding.
Until the thermal equilibrium is established between aluminium and copper wires the amount of heat that gets through both the wires will be same.
<em>But the rate of heat transfer through the aluminium will be greater as it has double the thermal conductivity of copper.</em>
Answer:
double
Explanation:
radius = r
length = l
Surface area, A = 2 π r l .... (1)
Now the radius is doubled = 2r
length is same
Surface area, A' = 2 x π x 2 r x l
A' = 2 x 2πrl
A' = 2 A (from equation (1)
Thus, the surface area is doubled.
Over time, the types of technology can vary and be improved upon so that more advanced techniques become more valued. This could be the situation with mining whereby back in the 1500's in underground mines the rock was broken by fire setting ie lighting a fire below the rock face to heat up the rock and then throwing cold water on it to crack it, so that it could be dug by hand. With the advent of explosives, this all changed so that the rock could be blasted. The increase in advance rates for an underground heading have thus gone from 5-20 feet per month to up to 300meters (984 ft) per month for a 24/7 mining operation, which is a huge improvement.
