Answer:
d. All of these
Explanation:
work is said to be done when a force is applied to an object through a certain distance. the SI unit of workdone is joules or newton per meter
mathematically
workdone = force x distance.
from the answers, work is being done because there is force applied in a certain distance.
- from wagon is used to carry vegetables from a garden.
- pulley is used to get water from a well.
- hammer is used to remove a nail from a wall.
The upward force exerted on the board by the support is 530.8 N.
<h3>Upward force exerted on the board by the support</h3>
The sum of the upward forces is equal to sum of downward forces;
total downward forces = 52.8 N + 206 N + 272 N = 530.8 N
downward force = upward force = 530.8 N
Thus, the upward force exerted on the board by the support is 530.8 N.
Learn more about upward force here: brainly.com/question/6080367
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Answer:
blue star is hotter than red
Explanation:
The colour of a star depends on its temperature.
Lesser the temperature means lesser be the energetic. less energy means longer wavelength. Between blue and red, red colour has longer wavelength. So, the red colored star is colder than blue coloured star.
Blue coloured star is hotter than red coloured star.
The answer is dark energy. This is the energy in the universe that opposes the gravitational attraction of matter in the universe. Initially, cosmologists had thought that the universe was decelerating due to the gravitational attraction between matter in the universe after the big bang. However, using the Doppler shift effect, evidence was gathered on the nature of the expansion of the universe.
Answer:
If T^2 = a^3
T1^2 / T2^2 = a1^3 / a2^3
Or T2^2 = T1^2 * ( a2^3 / a1^3)
Given T1 = 1 yr and a2 / a1 = 17
Then T2^2 = 1 * 17^3
or T2 = 70 yrs