The moon is moving away from Earth at a rate of approximately 3.78 cm per year.
This migration of the Moon from the Earth is mainly due to the action of the Earth tides. It can be explained as follows:
- the Moon exerts a gravitational force on the Earth, which is stronger at the Equator (since the Equator is closer to the Moon), creating the tides
- However, the Earth rotates faster on its axis (one rotation every 24 hours) than the Moon (one rotation every 27 days), therefore the tidal bulge on Earth tries to pull the Moon "ahead" in its orbit. As a result, the Moon tends to sped up.
<span>- As opposite reaction, the Earth tends to slow down in its rotation, with a loss of angular momentum. Since the angular momentum must be conserved, the radius of the orbit of the Moon becomes larger, and this explains why the Moon is moving away from the Earth.</span>
Answer: Option (b) is the correct answer.
Explanation:
Kinetic energy is the energy of an object or particle when it is in motion.
Mathematically, Kinetic energy = 
It is given that toy truck has mass = 0.75 kg, and velocity = 4 m/s.
Calculate the kinetic energy as follows.
Kinetic energy =
= 
= 
= 
= 
or, Kinetic energy = 6 joules
Thus, we can conclude that kinetic energy of toy truck is 6 J.
My answers would be as follows:
<span>You step on the scale and notice that you have lost five pounds. Which of the following has changed?
B) Only your weight changed since mass is conserved. It cannot be destroyed or created.
How could you increase the mass of a wooden block?
D) None of the above. Mass cannot be created so the mass will stay the same it will only be the weight you can increase depending on the acceleration.
If you went to the moon, how would your mass change relative to your mass on Earth?
A) It would be the same on the moon as on Earth. Mass will be the same. It is weight that will change since the gravitational acceleration in the moon is different as that to the earth.
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