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3 years ago

Which statement about metals is true?

1 answer:

4 0

All metals are solid at (our) living temperatures except for mercury which is a liquid. Metals are shiny for a while at least when properly finished. Metals are good conductors of both heat and electricity. This is due to the excess electrons in their valence clouds that facilitate energy transfer.What are 5 characteristics of metal?

Metals are lustrous, malleable, ductile, good conductors of heat and electricity

Silver conducts electricity better than any other metal.

Brass is an alloy made from zinc and copper.

Pure gold is too soft for many things so most gold is combined with other metals to make it stronger. ...

World time periods are often listed by the metal used.

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Mercury has one of the lowest specific heats. This fact added to its liquid state at most atmospheric temperatures make it effec

UNO [17]

The specific heat of mercury is 149.4 J/(kgK)

Explanation:

When a substance is supplied with an amount of energy Q, its temperature increases according to the equation:

$\Delta T=\frac{Q}{mC_s}$

where

$\Delta T$ is the increase in temperature

m is the mass of the sample

$C_s$ is its specific heat capacity

For the sample of mercury in this problem we have

Q = 275 J

m = 0.450 kg

$\Delta T = 4.09 K$

Therefore, by re-arranging the equation we find the mercury's specific heat:

$C_s = \frac{Q}{m\Delta T}=\frac{275}{(0.450)(4.09)}=149.4 J/(kgK)$

Learn more about specific heat capacity:

brainly.com/question/3032746

brainly.com/question/4759369

#LearnwithBrainly

5 0

3 years ago

The maximum tension that a 0.80 m string can tolerate is 15 N. A 0.35-kg ball attached to this string is being whirled in a vert

zimovet [89]

Answer:

v=5.86 m/s

Explanation:

Given that,

Length of the string, l = 0.8 m

Maximum tension tolerated by the string, F = 15 N

Mass of the ball, m = 0.35 kg

We need to find the maximum speed the ball can have at the top of the circle. The ball is moving under the action of the centripetal force. The length of the string will be the radius of the circular path. The centripetal force is given by the relation as follows :

$F=\dfrac{mv^2}{r}$

v is the maximum speed

$v=\sqrt{\dfrac{Fr}{m}} \\\\v=\sqrt{\dfrac{15\times 0.8}{0.35}} \\\\v=5.86\ m/s$

Hence, the maximum speed of the ball is 5.86 m/s.

3 0

3 years ago

The part of the building structure, typically below grade, upon which all other construction is built is known as:________

Degger [83]

Answer:

horizontal structural member that supports a floor. Beams are typically wood, cold formed metal framing or steel.

Joists

Horizontal timbers, beams or bars supporting a floor.

8 0

3 years ago

The 500 series bullet train travels between Tokyo and Hakata, Japan. If it is heading north with a momentum of 13,194,098.64 kg

Hitman42 [59]

Answer:

The mass of the 500 series bullet train is 181.4 tonnes.

Explanation:

The momentum is given by:

$p = mv$

Where:

m: is the mass =?

v: is the velocity = 261.8 km/h

p: is the momentum = 13194098.64 kg*m/s

By solving the above equation for "m" we have:

$m = \frac{p}{v} = \frac{13,194,098.64 kg*m/s}{261.8 km/h*\frac{1000 m}{1 km}*\frac{1 h}{3600 s}} = 181.4 tonnes$

Therefore, the mass of the 500 series bullet train is 181.4 tonnes.

I hope it helps you!

5 0

3 years ago

A car generates 2,552 N and weighs 2,250 pounds. what is the rate of acceleration

Lilit [14]

Ans: a = 2.50 m/s^2

Explanation:
First convert the mass in its standard unit i.e. kilogram(kg):
2250 lbs = 1020.583kg

Next use Newton's Second law:
F = ma

Where F = 2552N
m = 1020.583kg

=> a = (2552/1020.583)
a = 2.50 m/s^2

6 0

3 years ago