Physics, 17.09.2019 15:50 smithscarpetcaour4es

A60.0 kg object is moving east at 8.00 m/s, and then slows down to 4.00 m/s. how much work was done?
–1,440 j
–480 j
1,440 j
2,880 j

Answers: 2

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Answer from: gagem1278

Work done, W = -1440 J

Explanation:

It is given that,

Mas of an object, m = 60 kg

Initial velocity of the object, u = 8 m/s

Final velocity of an object, v = 4 m/s

We know that work done is equal to change in kinetic energy of an object as per work energy theorem.

$W=\dfrac{1}{2}mv^2-\dfrac{1}{2}mu^2$

$W=\dfrac{1}{2}m(v^2-u^2)$

Putting all the values in above equation we get :

$W=\dfrac{1}{2}\times 60\ kg((4\ m/s)^2-(8\ m/s)^2)$

W = -1440 J

So, the work done by the object is -1440 Joules. Hence, the correct option is (A) " -1440 J ".

Answer from: Quest

quantum mechanics or quantum physics is physics of very small objects (particles) and physical entities.

quantum physics has some parallels to our macro world and some pretty unique ideas which theoretically and mathematically proven to be true even though we will never be able to access them because of our size.

there are many types of particles: subatomic, elementary etc.

subatomic means they are smaller than atom, elementary means they are at the very basis of everything.

subatomic particles are for eg. protons, neutrons but not electrons.

elementary particles are categorised into 3 groups by what they do.

these 3 groups are quarks, leptons and bosons.

light for example is a particle more precisely a photon a part of leptons.

proton (subatomic particle) is made out of 2 up quarks and 1 down quark each of these has a fractional charge like $\frac{1}{3}$ . (i crazy)

most famous scientist who contributed to this physics are:

max planckalbert einsteinerwin schrödingermany

the topic itself us understand a lot and will probably be vastly used in the future (quantum computers, understanding the big bang,

we also must not forget quantum effects like:

superposition (where 1 thing can be this and that at the same time),entanglement (where two particles are seemingly connected by some sort of unknown (or known) force, energy, matter (i know all that can be the same at least it was at the beginning)

and there is more. but probably too much for this answer to be consistent due to my average understanding of this topic.

hope this you understand quantum mechanics a little more. i'm not an expert in the topic (so don't be like wth if you are an expert) but i'm very interested in it.

anyways quantum physics is a very hard topic (harder than physics (perhaps)) therefore searching for every information there is about it and learning it is unfortunately impossible (you can only specialise into 1 - 3 things or more (perhaps

have fun and i wish you luck!

r3t40

Answer from: Quest

we need to know the time interval during which the force acts. impulse of force = momentum change

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A60.0 kg object is moving east at 8.00 m/s, and then slows down to 4.00 m/s. how much work was done?...