Answer:
The acceleration due to gravity is times the value of g at the Earth’s surface.
(D) is correct option.
Explanation:
Given that,
Radius = 4000 miles
We need to calculate the gravitational force at surface
Gravitational force on the mass m on the surface of the earth
At r = R
....(I)
We need to calculate the gravitational force at height
Gravitational force on a mass m from the center of the earth,
At r = R + R = 2 R
....(II)
Dividing equation (II) by equation (I)
Hence, The acceleration due to gravity is times the value of g at the Earth’s surface.
Answer: B. II and III only
Explanation:
Let’s begin by explianing what energy is: the ability of matter to produce work in the form of movement, light, heat, among others. In this sense, there are several types of energy, but we will talk especifically in this case about <u>kinetic energy</u> and <u>potential energy</u>.
<u>Kinetic energy </u>is the energy an object or body has due to its movement and depends on the mass and velocity of the object or body.
To understande it better: If an object is at rest, its velocity is null and it does not have kinetic energy, however, if the object is moving, then it has kinetic energy.
On the other hand, <u>Potential energy</u> is known as <em>“stored energy”</em> that has the potential to be converted into energy of motion (kinetic energy) or another type of energy (thermal energy, for example). In addition, this energy is related to the work done when a certain force moves an object or body from its natural resting state along a distance to a new position.
So, according to this, Kinetic energy can be transformed into potential energy and Potential energy can be transformed into kinetic energy or any other type of energy. Hence, options II and III are correct.
It has been hypothesized, and some studies have supported the conjecture,
that certain species of insects and birds are able to sense the direction of external
magnetic fields.
I don't think there is any such notion where human beings are concerned.
Answer:
C. Supervising the game to make sure teams are playing fairly
<span> y=y0 + vt +1/2gt^2
(solve for t here) cause you know y,y0,v,g
you will do quad formula here
then:
v=v0 +at solve for v
(remember the direction of the ball too (signs))
The main thing to remember here is that when the ball passes exactly (height) where it was launched it will travel the speed at which it was launched. *its almost like the ball was thrown in the downward direction. </span>