If the sign of work is negative, that means the force and the motion are in opposite directions.
Let's say you see something roll off of the shelf. You catch it, and you let it down slowly and gently.
Gravity exerted down-force on it and it moved down. Gravity did positive work on it.
YOU exerted UP-force on it and it moved down. YOU did negative work on it.
(Also, the falling object exerted down-force on your hand, and your hand moved down. The falling object did positive work on your hand ! Where did THAT energy come from ? It came from the potential energy that the object had while it was on the shelf. Your hand absorbed that energy on the way down, doing negative work. So the object didn't have any kinetic energy when it reached the floor, and it did NOT splinter the floor or shatter in smithereens. It had barely enough energy left to make a sound when it hit the floor.)
Answer:
<em>x=6.39 m</em>
Explanation:
<u>Rectangular Components of a Vector</u>
Vectors can be expressed in several forms, including the magnitude-angle form, and the rectangular-coordinates form.
If the magnitude r and angle β are given, we can find the rectangular coordinates (x,y) as follows:
The vector of the question has a magnitude of r=9.55 m and an angle β=-48°. The x-component is:
Using a digital calculator:
x=6.39 m
Answer:
B
Explanation:
Fermium is a synthetic element with the symbol Fm and atomic number 100. It is an actinide and the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not yet been prepared.[3] A total of 19 isotopes are known, with 257Fm being the longest-lived with a half-life of 100.5 days.
It was discovered in the debris of the first hydrogen bomb explosion in 1952, and named after Enrico Fermi, one of the pioneers of nuclear physics. Its chemistry is typical for the late actinides, with a preponderance of the +3 oxidation state but also an accessible +2 oxidation state. Owing to the small amounts of produced fermium and all of its isotopes having relatively short half-lives, there are currently no uses for it outside basic scientific research.
Answer: 207 W
Explanation: I assumed here that the object is moved vertically. If that is the case, the work done on the object is equal to its change in gravitational potential energy:
where
m = 47 kg is the mass of the object
g = 9.8 m/s^2 is the acceleration of gravity
is the change in height
Substituting,
Now we can calculate the power used, which is given by
Hope this helps I'm sorry if i'm wrong but I tried :(
The correct answer is:
That the land where it specifically was has been moving and that years ago that place was under water.
Explanation:
Kansas has been the cause of some of the most luxurious fossil findings in US history. The fossil record of Kansas spans from the Cambrian to the Pleistocene. From the Cambrian to the Devonian, Kansas was coated by a shallow sea.