Read over slides 1-7 to see definitions and map examples of each physical feature.

Which of the following statements about energy is true? I. Kinetic energy cannot be transformed into another type of energy. II.

Mashcka [7]

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 kinetic energy and potential energy.

Kinetic energy 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, Potential energy is known as “stored energy” 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.

8 0

3 years ago

Read 2 more answers

A ball is whirled on the end of a string in a horizontal circle of radius R at constant speed v. Complete the following statemen

Eva8 [605]

Answer:

Keeping the speed fixed and decreasing the radius by a factor of 4

Explanation:

A ball is whirled on the end of a string in a horizontal circle of radius R at constant speed v. The centripetal acceleration is given by :

$a=\dfrac{v^2}{R}$

We need to find how the "centripetal acceleration of the ball can be increased by a factor of 4"

It can be done by keeping the speed fixed and decreasing the radius by a factor of 4 such that,

R' = R/4

New centripetal acceleration will be,

$a'=\dfrac{v^2}{R'}$

$a'=\dfrac{v^2}{R/4}$

$a'=4\times \dfrac{v^2}{R}$

$a'=4\times a$

So, the centripetal acceleration of the ball can be increased by a factor of 4.

7 0

3 years ago

Two bicyclist, originally separated by a distance of 20 miles, are each traveling at a uniform speed of 10 miles per hour toward

Radda [10]

Answer:

D = 25 miles

Explanation:

To solve this problem, we just need to know how much time it took both bicyclists to collide and that will be the same amount of time that the bee flew at 25miles per hour. With those values we could calculate the distance it traveled.

Since both bicyclists collide, we know that Xa=Xb, so:

Xa = V*t = 10*t and Xb = 20 - V*t = 20 - 10*t

10*t = 20 - 10*t Solving for t:

t = 1 hour Now we can calculate the distance for the bee:

D = Vbee * t = 25 * 1 = 25 miles

6 0

3 years ago

If a football player collides with a goal post, what forces are at work?

AlekseyPX

When a footballer collides with the goal post, the forces at work are the action and reaction forces. The player will exert an action force on the goal post, and then a reaction force from the goal post will stop the player. The reaction force call will cause pain and even injury to the player.

7 0

3 years ago

What are most fossils discovered in

erik [133]

Sedimentary rock I believe

4 0

3 years ago