Answer:
-223.64684 J
Explanation:
F = Force that is applied to the crate = 68 N
s = Displacement of the crate = 3.5 m
= Angle between the force and displacement vector = (180-20)
Work done is given by

The work that Paige does on the crate is -223.64684 J
"The distance that the force moves" is the one among the following choices given in the question that must be increased, if a simple machine reduces the strength of a force. The correct option among all the options that are given in the question is the first option or option "A". I hope the answer helped you.
Every element is able to be recognized individually in many different ways. A very easy and common way is using light absorption also known as spectroscopy. Every atom has electrons, and these electrons like to stay in their lowest-energy configuration. However, when photons collide with an electron it can increase it to a higher energy level.. This is absorption, and each element’s electrons absorb light at specific wavelengths related to the difference between energy levels in that atom. But the electrons want to return to their original levels, so they don’t hold onto the energy for long. When they emit the energy, they release photons with exactly the same wavelengths of light that were absorbed in the first place. An electron can release this light in any direction, so most of the light is emitted in directions away from our line of sight. Therefore, a dark line appears in the spectrum at that particular wavelength.
Because the wavelengths at which absorption lines occur are unique for each element, astronomers can measure the position of the lines to determine which elements are present in a target. The amount of light that is absorbed can also provide information about how much of each element is present.
Answer:
efficiency of engine is 0.21
Explanation:
given:
Th=980 K
Tc=570 K
since efficiency of engine is given as:
n=3/5*n_m
=3/5(1-Tc/Th)
=0.21
efficiency of engine is 0.21
Answer:
C) 20 m/s
Explanation:
Wave: A wave is a disturbance that travels through a medium and transfers energy from one point to another, without causing any permanent displacement of the medium itself. Examples of wave are, water wave, sound wave, light rays, radio waves. etc.
The velocity of a moving wave is
v = λf ............................ Equation 1
Where v = speed of the wave, λ = wave length, f = frequency of the wave.
Given: f = 2 Hz (two complete cycles in one seconds), λ = 10 meters
Substituting these values into equation 1
v = 2×10
v = 20 m/s.
Thus the speed of the wave = 20 m/s
The right option is C) 20 m/s