Answer:
W = 71J
Explanation:
Given force F = (5i+5j−1k)N
d = Δr
r1 = (−5,−3,−4)m
r2 = (2,5,0)m
Δr = r2 – r1 = (2-(-5), 5-(-3), 0-(-4))
Δr = (2+5, 5+3, 0+4) = (7i+ 8j +4k)m
W = F•d = (5i+5j−1k)•(7i+ 8j +4k)
W = 5×7 + 5×8 +-1×4 = 35 + 40 - 4
W = 71J
White dwarfs
<u>Explanation:</u>
Hertzsprung-Russel graph is a 2-dimensional graph, plotting star’s luminosity against temperature they emit.
White dwarfs are the star exhibiting high temperatures and low luminosities. These stars are extremely dense and mass comparable to that of the sun.
The main cause of low luminosities in the absence of fusion reaction inside the core of the star. Faint luminosity is provided by the thermal energy of the star. They are considered to be in the final stage of evolution having masses in the range of 10 solar mass (hence not enough to form a star)
Answer:
Option (a)
Explanation:
We will discard options that don't fit the situation:
Option b: <em>Incorrect </em>since if the driver "hits the gas" then velocity is augmenting and it's not constant.
Option c and d: <em>Incorrect </em>since the situation doesn't give us any information that could be related directly to the terrain or movement direction.
Option a: Correct. At <em>stage 1</em> we can assume the driver was going at constant speed which means acceleration is constantly zero. At <em>stage 2 </em>we can assume the driver augmented speed linearly, this is, with constant positive acceleration. At <em>stage 3 </em>we can assume the driver slowed the speed linearly, with constant negative acceleration.
C because mass is how much space an object takes up
Number of barrels are 3.0. Each barrel contains 42 gallons of oil. Thus, total volume of oil will be 42×3=126 gallons.
Converting gallons into m^{3}
1 gallon=0.00378 m^{3}
Thus, 126 gallons=0.4769 m^{3}
Thickness of oil film is 2.5\times 10^{2} nm, converting it into meters as follows:
1 nm=10^{-9} m
Thus,
2.5\times 10^{2} nm=1.5\times 10^{-7}m
Now, volume V of oil is related to area A and thickness T as follows:
V=A×T
rearranging,
A=\frac{V}{T}=\frac{0.4769 m^{3}}{2\times 10^{-7}m}=2.38\times 10^{6}m^{2}
Thus, square meters of oil will be 2.38\times 10^{6}m^{2}
