Answer:

Explanation:
Regardless of the initial velocity of the pebble, the acceleration of the pebble is equal to the gravitational acceleration which is equal to 9.8 m/s2 towards downwards direction.
This can be shown by Newton's Second Law. According to the law, the net force applied on an object is equal to mass times acceleration of that object.
During the downward motion, the only force acting on the pebble is the gravitational force, hence its acceleration is equal to gravitational acceleration.
Answer:
What is most widely accepted today is a the giant-impact theory. It proposes that the Moon formed during a collision between the Earth and another small planet, about the size of Mars. The debris from this impact collected in an orbit around Earth to form the Moon.
Answer:
I like to memorize excerpt from articles to solve and answer questions like these. I hope this can help, it's from study.com: "The relationship between voltage, current, and resistance is described by Ohm's law. This equation, i = v/r, tells us that the current, i, flowing through a circuit is directly proportional to the voltage, v, and inversely proportional to the resistance, r."
Answer:
positive, positive
You throw a rock upward. The rock is moving upward, but it is slowing down. If we define the ground as the origin, the position of the rock is positive and the velocity of the rock is positive
Explanation:
Given that the ground is defined as the origin.
The position of the rock is positive since the rock is thrown upward, the position also increases with time until it reaches the maximum height. Also, since the rock is thrown upward with the ground as the origin, the velocity of the rock is positive but the velocity reduces with time (change in height per unit time as the rock moves up is positive)
Answer:
The correct answer is B: the kinetic energy of the heavier block is equal to the kinetic energy of the lighter block.
Explanation:
Hi there!
The work done on each block is calculated as follows:
W = F · d
Since the two blocks were pushed the same distance with the same force, the work done on each object is the same.
Using the work-energy theorem, we know that the work done on an object is equal to its change in kinetic energy (KE):
W = ΔKE
W = final KE - initial KE
Since the objects are at rest, initial KE = 0, then:
W = final KE
Since the work done on each block is the same, so will be its final kinetic energy.
The correct answer is B: the kinetic energy of the heavier block is equal to the kinetic energy of the lighter block.