Physics, 30.03.2020 17:49 daniellaZemira

A river 91.4 m wide flows toward the south at 33.6 m/min. A girl on the west bank wishes to reach the east bank in the least possible time. She can swim 91.4 m in still water in 2.00 min. (a) How long does it take her to cross the river

Answers: 3

Show answers

Answers

Answer from: jamarcuswilliam2515

2.0 min

Explanation:

We are given that

Width of river,d=91.4 m

Time,t=2 min

Rate of flowing water of river=33.6/min

We have to find the time taken by girl to cross the river.

Speed of girl= $v=\frac{distance}{time}=\frac{91.4}{2}=45.7m/min$

Time taken by girl= $\frac{distance}{speed}$

Using the formula

Time taken by girl= $\frac{91.4}{45.7}$

Time taken by girl=2.0 min

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

32: from largest to smallest, this hierarchy includes eons, eras, periods, epochs, and ages.

33: answer is c

i really hope this answer you out! it makes my day people like you and giving back to the community that has me through school! if you could do me a favor, if this you and this is the very best answer and you understand that all of my answers are legit and top notch. mark as brainliest! and have a awesome day!

Other questions on the subject: Physics

Physics, 22.06.2019 17:40, cravens511peeelg

The first-order reaction a→2b+c has rate constant 0.538 s−1. if the initial concentration of a is 0.867 mol l−1, what is the half-life of the reaction in seconds? remember to use correct significant figures in your answer (round your answer to the nearest hundredth). do not include units in your response.

Answers: 3

continue

Physics, 23.06.2019 00:20, bighoneypadrick

An object with a mass of 1.5 kg changes its velocity from + 15 m/s to +22 m/s during a time interval of 3.5 seconds. what impulse was delivered to the objects?

Answers: 2

continue

Physics, 23.06.2019 08:30, lalkjlkeu9709

Because air contracts as it cools, the air pressure inside a freezer is typically lower than on the outside. why do ice cubes inside a freezer tend to shrink over time? the ice sublimes, and then the water vapor deposits as ice crystals on the sides of the freezer. the ice melts, and then the liquid freezes as ice crystals on the bottom of the freezer. the ice dissolves oxygen from the air, forming a denser crystalline matrix. the ice reacts chemically with carbon dioxide in the air, forming gaseous carbon compounds.

Answers: 1

continue

Physics, 23.06.2019 10:10, jewelia2801

The heat fusion is the amount of heat required to__ a- evaporate 1 g of liquid into gas b-make a substance subliminate c- melt 1g of solid into liquid d-make material combust

Answers: 2

continue

You know the right answer?

A river 91.4 m wide flows toward the south at 33.6 m/min. A girl on the west bank wishes to reach th...