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2 years ago

A train travels at a speed of 30 miles/hour and traveled a distance of 240 miles. How

1 answer:

7 0

Since the train travels 30 miles per hour, you can divide the total distance by the miles per hour to get the time, so it takes 240mi/30 mph, which is 8 hours, since the mile units cancel themselves out

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In the following diagrams the larger vector has a magnitude of 10, and the smaller

Anton [14]

the sum of vectors with the Pythagorean theorem allows us to find that the maximum magnitude occurs for the case:

d) the two vectors are parallel

Vectors are physical quantities that have modulus and direction, for example: force, velocity, acceleration, etc.

Vector algebra has defined the sum, the product by a scalar and by a vector. The modulus and the direction of the resulting vector must be encoded.

The sum of two quantities is done using the Pythagorean theorem

c² = a² + b²

where c is the resultant called hypotenuse, a and b are the summing vectors called legs; trigonometry is used for the direction.

Let's apply this expression to the present case

a, b) perpendicular vectors

c² = a² + b²

c = $\sqrt{6^2+10^2}$

c = 11.7

the magnitude is the same in both cases, changing the direction of the vector

c) Antiparallel vectors

For this case the vectors are collinear, so the sum reduces to the algebraic addition

c = a-b

c = 6 -10

c = -4

d) parallel vectors

c = a + b

c = 4 + 10

c = 14

We can see that the vectors addition gives their maximum and minimum values when the vectors are collinear.

In conclusion using the vectors addition we find that the correct answer is

d) the two vectors are parallel

learn more about vector addition here:

brainly.com/question/15074838

6 0

2 years ago

You throw a glove straight upward to celebrate a victory. Its initial kinetic energy is K and it reaches a maximum height h. Wha

Rasek [7]

Answer:

K/2

Explanation:

The law of conservation of mechanical energy states that the sum of the kinetic and potential energies is a constant at any point.

At maximum height, the glove has purely potential energy but at the bottom, it has purely kinetic energy.

The potential energy at the top = kinetic energy at the bottom. The potential energy is given by

$PE = mgh$

At half height, this potential energy is

$PE = \frac{1}{2}mgh$

At this height, PE + KE = Constant = KE at bottom or PE at maximum height.

$mgh = \frac{1}{2}mgh +KE$

$KE = \frac{1}{2}mgh = K/2$

5 0

3 years ago

You measure the power delivered by a battery to be 4.26 W when it is connected in series with two equal resistors. How much powe

gtnhenbr [62]

Answer:

<em>The power delivered by the battery is 17.04 W</em>

Explanation:

Power through a circuit is given as

P = IV ....1

where P is the power

I is the current through the circuit

V is the voltage through the circuit

The voltage in a circuit is given as

V = IR ....2

Let us take the value of each resistor as equal to R

when connected in series, the total resistance will be

$R_{t}$ = R + R = 2R

If we assume constant voltage through the circuit, then from equation 2, the current in this case is

I = V/2R

If the resistors are connected in parallel, then the total resistance will be

$\frac{1}{R_{t} }$ = $\frac{1}{R}$ +

$R_{t}$ = R/2

The current in this case will be increased since the resistance is reduced

I = 2V/R

comparing the two situations, we can see that the current increased when connected in parallel to a ratio of

$\frac{2V}{R}$ ÷ $\frac{V}{2R}$ =

This means that the current increased 4 times

From equation 1, we can see that electrical power is proportional to the current at a constant voltage, therefore, the power will also increase by four times to

P = 4 x 4.26 = <em>17.04 W</em>

3 0

3 years ago

Using your best estimates, how many times would you have to slap a 1 kg rotisserie chicken in order to cook it? You can assume t

FromTheMoon [43]

Answer:

n= 16021.03 slaps

Explanation:

Using law of Energy conservation

E_{thermal}= Kinetic energy of hand

⇒ $mc\Delta T= n\frac{1}{2}m_hv_h^2$

m_h= mass of the hand = 0.4 kg

v_h= velocity of the hand = 10 m/s

n= number of slaps

c= 4180 J/Kg °C

m= mass of chicken = 1 kg

Assuming all the energy of hand goes into chicken

Given Ti=0°C and T_f= 170 F= 76.66°C

Now putting the values in above equation to get n

$1\times4180(76.66)= n\frac{1}{2}0.4\times10^2$

n= 16021.03 slaps

8 0

2 years ago

The mass of a radioactive substance follows a continuous exponential decay model, with a decay rate parameter of 1% per day. A s

Bumek [7]

Answer:

2,38kg

Explanation:

Mass in function of time can be found by the formula: $m_{(t)} =m_{0} e^{-kt}$ , where $m_{0}$ is the initial mass, t is the time and k is a constant.

Given that a sample decay 1% per day, that means that after first day you have 99% of mass.

$m_{(1)} =m_{0} e^{-k(1)}$ , but $m_{(1)}=\frac{99m_{0} }{100}$ , so we have $\frac{99m_{0} }{100}=m_{0}e^{-k}$ , then $k=-ln(\frac{99}{100})=0.01$

Now using k found we must to find $m_{(5)}$ .

$m_{(5)}=m_{0}e^{-(0.01)5}=2.5kge^{-0.05} =2.5x0.951=2.38kg$

6 0

2 years ago