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ludmilkaskok [199]

2 years ago

15

When Mendeleev organized elements in his periodic table in order of increasing mass, similar elements with similar properties we

re in the same (Blank)

1 answer:

Temka [501]2 years ago

8 0

Similar elements with similar properties were in the same groups and periods for instance lithium(Li) and sodium(Na) are alkaline metals and so belong to the same group (that is group 1).Also Hydrogen(H) and Helium(He) both have only one shell or energy level and so belong to the same period.

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How you do this resistor in circuit question?

lawyer [7]

If Resistors are in series= The equivalent is the sum.

E.g R1 and R2 in series, R = R1 + R2.

If in Parallel, equivalent is Product/sum.

E.g If R1 and R2 in parallel, R = (R1*R2)/(R1+R2)

1.) 60 is parallel with 40 and both are then in series with 20.

60//40 = (60*40)/(60+40) = 2400/100 = 24

Now the 24 is in series with the 20

R = 24 + 20 = 44 ohms.

2.) 80 is in series with 40 and both are then in parallel with 40.

Solving the series, R = 80 + 40 =120.

Parallel: 120//40 = (120*40)/(120+40) = 4800/160 = 30
Equivalent Resistance = 30 ohms.

3.) 100 is in parallel with 100 and both are then in series with the parallel of 50 and 50.

The 1st parallel = (100*100)/(100+100) = 10000/200 = 50

The 2nd parallel = (50*50)/(50+50) = 2500/100 = 25.

Solving the series = 50 + 25 =75 ohms.

Cheers.

3 0

2 years ago

When astronauts aboard the space shuttle look down at the earth, its atmosphere appears blue. Why?.

Alex777 [14]

Answer:

Reflection

Explanation:

<em>The particles in the atmosphere only reflect the color blue and and all others are absorbed. Only the reflected colors can be seen from our eyes not the absorbed ones</em>

8 0

1 year ago

A train travels 59 kilometers in 3 hours, and then 74 kilometers in 5 hours. What is its average speed?

dybincka [34]

Average speed = (total distance) / (total time)

Total distance = 59 km + 74 km = 133 km

Total time = 3 hrs + 5 hrs = 8 hrs

Average speed = (133 km) / (8 hrs) = 16.625 km/hr

3 0

2 years ago

Jack and Jill are maneuvering a 3300 kg boat near a dock. Initially the boat's position is < 2, 0, 3 > m and its speed is

Paraphin [41]

Answer:

The workdone by Jack is $W_{jack} = -1050J$

The workdone by Jill is $W_{Jill} = 0J$

The final velocity is $v = 1.36 m/s$

Explanation:

From the question we are given that

The mass of the boat is $m_b = 3300kg$

The initial position of the boat is $P_i = (2 \r i + 0 \r j + 3\r k)m$

The Final position of the boat is $P_f = (4\r i + 0 \r j + 2\r k )\ m$

The Force exerted by Jack $\r F = (-420\r i + 0 \r j + 210\r k) \ N$

The Force exerted by Jill $\r F_{Jill} =(180 \r i + 0\r j + 360\r k)$

Now to obtain the displacement made we are to subtract the final position from the initial position

$\r P = P_f - P_i$

$= (4\r i + 0\r j + 2 \r k) - (2\r i + 0\r j + 3\r k )$

$= (2\r i + 0\r j -\r k )m$

Now that we have obtained the displacement we can obtain the Workdone

which is mathematically represented as

$W =\r F * \r P$

The amount of workdone by jack would be

$W_{jack} =\r F * \r P$

$= [(-420\r i +0\r j +210\r k)(2\r i + 0\r j - \r k)]$

$= (-420) (2) + (210)(-1)$

$= -840 - 210$

$=-1050J$

The amount of workdone by Jill would be

$W_{Jill} =\r F * \r P$

$= [(180 \r i + 0\r j + 360\r k)(2\r i +0\r j -\r k)]$

$= (180 )(2) +(360)(-1)$

$=0J$

According to work energy theorem the Workdone is equal to the kinetic energy of the boat

$W = K.E = \frac{1}{2} m *[v^2 - (1.1)^2]$

$-1050 = 0.5*3300 [*v^2- (1.1)^2]$

$-1050 = 1650 [v^2 -1.21]$

$0.6363 = v^2 -1.21$

$v^2 = 0.6363+1.21$

$v^2 =1.846$

$v = 1.36\ m/s$

6 0

3 years ago

Electromagnetic induction occurs when

aksik [14]

Answer:

A

Explanation:

occurs when a magnetic feild and an elctric conductor move relative to one another

5 0

2 years ago