Hi there!
We can use the work-energy theorem to solve.
Recall that:
The initial kinetic energy is 0 J because the crate begins from rest, so we can plug in the given values for mass and final velocity:
Now, we can define work:
Now, plug in the values:
Solve for theta:
Answer: B. The gravitational field strength of Planet X is Wx/m.
Explanation:
Weight is a force, and as we know by the second Newton's law:
F = m*a
Force equals mass times acceleration.
Then if the weight is:
Wx, and the mass is m, we have the equation:
Wx = m*a
Where in this case, a is the gravitational field strength.
Then, isolating a in that equation we get:
Wx/m = a
Then the correct option is:
B. The gravitational field strength of Planet X is Wx/m.
Answer: The correct answer is B. "the electromagnetic waves appear more red in color".
Explanation:
Scientists use the Doppler effect to understand the universe by determining the motion of the object.
Red shift: The apparent frequency of light decreases as the source object in space moves away from us. The light is shifted to red end. The apparent frequency decreases and there is increase in the wavelength of the light.
Blue shift: The apparent frequency of light increases as the object in space moves towards us. The light is shifted to blue end. In this case, there is decrease in the wavelength of the light. The frequency of the wave increases.
In the given problem, when the light source moves further away from an observer, the electromagnetic waves appear red in color.
Therefore, the correct option is (B).
