Answer:
Option B is the correct answer.
Explanation:
Thermal expansion
L = 1.2 meter
ΔT = 65 - 15 = 50°C
Thermal Expansion Coefficient for aluminum, α = 24 x 10⁻⁶/°C
We have change in length
New length = 1.2 + 1.44 x 10⁻³ = 1.2014 m
Option B is the correct answer.
Answer:
1.06 metres per second squared
Explanation:
since friction acts against foward force
20 N - 4 N = 16 N
use Newtons 2nd law F=ma Solve for a:
a= F÷m
= 16 ÷ 15
= 1.06 metres per second squared
Astronomers believe some stars are moving away from earth by measuring the extent to which their light is “stretched” into the red part of the color spectrum, representing the lower frequencies on that spectrum.
In short, stars moving away from earth are “red-shift”, while if they were moving towards the earth they would take on a “blue-shift”.
If you stand up in a big room and echo, your voice will echo
from the walls. As long as the room is empty. Since
the speed of sound is constant, depending on air density, the more humid the
air the faster and farther sound travels. The
speed of sound is constant, you could measure the time it takes for your voice
to echo off the walls. The same thing happens with Doppler radar, but it’s not voice,
it has higher frequency signals.<span> </span>
