A car moving has a speed of 35 m/s. What acceleration would it have if it took 5.0 s to come to a complete stop?

A river has a steady speed of 0.566 m/s. A student swims upstream a distance of 1.57 km and returns (still swimming) to the star

MArishka [77]

Answer:

3503.72 seconds

819.96 seconds

Explanation:

$V_r$ =Velocity of river = 0.566 m/s

$V_s$ =Velocity of student = 1.17 m/s

Distance to travel = 1.57 km = 1570 m

So,

Time = Distance / Speed

$\frac{1570}{V_s-V_r}+\frac{1570}{V_s+V_r}=t\\\Rightarrow t=\frac{1570}{1.17-0.566}+\frac{1570}{1.17+0.566}\\\Rightarrow t=3503.72\ s$

Time taken by the student to complete the trip is 3503.72 seconds

In still water

$\frac{1570}{V_s}+\frac{1570}{V_s}=t\\\Rightarrow t=\frac{1570}{1.17}+\frac{1570}{1.17}\\\Rightarrow t=2683.76\ s$

The difference in time between moving water and still water is 3503.72-2683.76 = 819.96 seconds

5 0

3 years ago

Aluminium,metal,glass,and paper:

Travka [436]

Aluminum metal is a good example of conductor of electricity while glass and paper are good example of insulators.

<h3>What is a conductor?</h3>

A conductor is material that allows easy passage of electric current through the.

<h3>Examples of conductors</h3>

All metals are good examples conductors. such as aluminum, iron, silver, etc.

<h3>What is a non conductor?</h3>

A non conductor or insulator is a material which does not allow easy passage of electric current through them.

<h3>Examples of insulators</h3>

glass
paper
wood, etc

Thus, aluminum metal is a good example of conductor of electricity while glass and paper are good example of insulators.

The complete question is below:

aluminium,metal,glass,and paper, are examples of what?

Learn more about conductors here: brainly.com/question/24154868

#SPJ1

7 0

2 years ago

(Double points) A machine receives electricity that enables it to deliver a total of 8,542 N of force for the completion of its

storchak [24]

Answer: machine's efficiency = 82.2%

Explanation:

Efficiency of a machine is the capability of a machine to convert input to output without waste.

It can be expressed as

Efficiency = output/ input × 100%

Output = 7,023N

Imput = 8,542N

Efficiency = 7,023N/8,542N × 100%

Efficiency = 82.2%

4 0

3 years ago

you push a ball to star it rolling along a "perfectly frictionless" surface. How far will the ball roll

-BARSIC- [3]

Technically, it should roll forever.

6 0

3 years ago

When a fixed amount of ideal gas goes through an isobaric expansion A) its internal (thermal) energy does not change.B) the gas

Bingel [31]

<h2>Answer: its temperature must increase.</h2>

Explanation:

In an isobaric process the pressure remains constant, which means the initial pressure and the final pressure will be the same.

In addition, during this thermodynamic process, the volume of the ideal gas expands or contracts in such a way that the variation of pressure $\Delta P$ is neutralized.

Now, according to the First law of Thermodynamics that establishes the conservation of energy:

$\Delta U=\Delta Q-\Delta W$ (1)

Where:

$\Delta U$ is the internal energy

$\Delta Q$ is the heat transferred

$\Delta W$ is the work

Now, for an isobaric process:

$\Delta W=P\Delta V$ (2)

Where:

$P$ is the pressure (<u>always positive</u>)

$\Delta V$ is the volume variation of the gas

<u />

<u>Here we have two possible results:</u>

-If the gas expands (positive $\Delta V$ ), the work is positive.

-If the gas compresses (negative $\Delta V$ ), the work is negative.

In this case we are talking about the first result (work is positive).

Then, according to the above, equation (1) can be written as follows:

$\Delta U=\Delta Q - P\Delta V$ (3)

Clearing $\Delta Q$ :

$\Delta Q=\Delta U+P \Delta V$ (4)

Then, for an ideal gas in an isobaric process, part of the heat ( $Q$ ) added to the system will be used to do work (positive in this case) and the other part <u>will increase the internal energy</u>, hence <u>the temperature will increase as well.</u>

7 0

3 years ago