Work done is given by the change in kinetic energy of an object
- The kinetic energy of the shovel, the shrub, and in Robert's movement were changed, therefore, work is done in the given processes,
Reason:
Work is done when the total energy of object is affected by the application of force on the object over a distance
Therefore;
- In option <em>A</em>, pushing the shovel into ground (to dig out the dirt) the requires the application of a force (push) over a distance, (into and out of the ground) therefore work is done
- In option <em>B</em>, picking the shrub up gives it gravitational potential energy, therefore, work is done
- In option <em>C</em>, carrying the shrub to the hole does visible work
- In option <em>D</em>, holding the shrub while lowering it into the hole does work by preventing the shrub from falling randomly
Therefore, <u>work is done in the given processes</u>
Learn more about work-energy theorem here:
brainly.com/question/10063455
Explanation:
Tea cools faster in a cup than in a kettle because when it is on a cup it is more spread out so the cooler air around it is able to cool down each molecule faster than if it were in a kettle which is cooling down slower because the tea is not a spread out
Vehicles equipped with disc brakes incorporate a mechanically operated drum-style parking brake in the center of the rear disc brake rotors, commonly called a top hat parking brake.
<h3>What is top hat parking brake?</h3>
The top hat drum style of parking brake system is called the top hat rotors because of how big the middle part is compared to regular rotors.
In this type of parking brake system, the vehicle is equipped with disc brakes which incorporate a mechanically operated drum-style parking brake in the center of the rear disc brake rotors.
Thus, vehicles equipped with disc brakes incorporate a mechanically operated drum-style parking brake in the center of the rear disc brake rotors, commonly called a top hat parking brake.
Learn more about top hat parking brake here: brainly.com/question/21854030
In the photoelectric effect, the energy given by the incoming photon is used partially to extract the electron from the metal (work function) and the rest is converted into kinetic energy of the electron:
where
hf is the energy of the photon, with h being the Planck constant and f the frequency of the photon
is the work function
K is the kinetic energy of the electron
When K=0, we have the minimum energy required to extract the electron from the metal, so the equation becomes
(1)
If we convert the work function of gold into Joules:
We can re-arrange eq.(1) to find the minimum energy of the photon:
The correct answer is <u>B. Where crust is destroyed.</u>
