How many significant figures does each of the following numbers have?

Which of the following material offers the lowest resistivity?

Yuki888 [10]

Lower resistivity means higher conductivity: among these materials, the best conductor is silver, therefore it must be the material with lowest resistivity among those. We can also have a look at the value of resistivity of the different materials listed in the problem, to check our answer. The resistivities of the materials are the following:
Wood: $1.00\cdot 10^{3} \Omega \cdot m$
Salt water: $2.00\cdot 10^{-1} \Omega \cdot m$
Silver: $1.59\cdot 10^{-8} \Omega \cdot m$
Lead: $2.20\cdot 10^{-7} \Omega \cdot m$
<span>We see that the material with lowest resistivity among those is silver, therefore the correct answer is silver.</span>

7 0

3 years ago

Read 2 more answers

Click to review the online content. Then answer the question(s) below, using complete sentences. Scroll down to view additional

mamaluj [8]

Answer:

here try this! i hope this helps

Explanation:

There are many advantages when we compare strength training with other forms of training. For example, the biggest benefit would be the increase of muscle mass due to us using the muscle more and for harder movements than usual. Strength training can preserve the mass that we lose with age. Bones also get stronger when we train so they are harder to fracture. We get more joint flexibility from the movements we do. So things as arthritis can be avoided or at least feel better.

8 0

3 years ago

Read 2 more answers

Zinc can not be changed into a simpler substance by a chemical or physical process. Therefore, zinc is classified as:

bonufazy [111]

The correct answer I think is a compound

7 0

3 years ago

What is the difference between transverse and longitudinal waves?

Fed [463]

To explain how transverse and longitudinal waves work, let us give two examples for each particular case.

In the case of transverse waves, the displacement of the medium is PERPENDICULAR to the direction of the wave. One way to visualize this effect is when you have a rope and between two people the rope is shaken horizontally. The shift is done from top to bottom. This phenomenon is common to see it in solids but rarely in liquids and gases. A common application usually occurs in electromagnetic radiation.

On the other hand in the longitudinal waves the displacement of the medium is PARALLEL to the direction of propagation of the wave. A clear example of this phenomenon is when a Slinky is pushed along a table where each of the rings will also move. From practice, sound waves enclose the definition of longitudinal wave displacement.

Therefore the correct answer is:

C. In transverse waves the displacement is perpendicular to the direction of propagation of the wave, while in longitudinal waves the displacement is parallel to the direction of propagation.

8 0

4 years ago

Consider a wet banked roadway, where there is a coefficient of static friction of 0.30 and a coefficient of kinetic friction of

gulaghasi [49]

Answer:

a) v = 20.9 m/s

b) v = 8.46 m/s

Explanation:

Given:-

- The coefficient of static friction is us = 0.30

- The coefficient of static friction is uk= 0.25

- The radius of the curve R = 50m

- The bank Angle β = 25

Find:-

a) If the banking angle is β=25∘, what is the maximum speed the automobile can have before sliding up the banking?

b) What is the minimum speed the automobile can have before sliding down the banking?

Solution:-

- We will investigate the sliding-up case first. Develop a FBD as given in (attachment).

- Use Newton's second law of motion vertical to slope of bank where the car is in equilibrium:

Sum ( F_n ) = 0

N*cos(β) - m*g - Ff*sin(β) = 0

Where, Frictional Force Ff = us*N

N (cos(β) - us*sin(β)) = mg ... Eq 1

- Use Newton's second law of motion horizontal to slope of bank where the car is accelerating:

Sum ( F_h ) = m*a

Ff*cos(β) + Nsin(β) = m*v^2 / R

N (us*cos (β) + sin (β) ) = m*v^2 / R .... Eq 2

- Divide the two equations:

v^2 / gR = [ us*cos (β) + sin (β) ] / [ cos (β) - us*sin (β) ]

v^2 = [ 0.25*cos (25) + sin (25) ]*9.81*50 / [ cos (25) - 0.25*sin (25) ]

v = 20.9 m/s

- For the slip down case. We have, friction force Ff reversed hence us = -us. Then the v can be given as:

v^2 / gR = [ -us*cos (β) + sin (β) ] / [ cos (β) + us*sin (β) ]

v^2 = [ -0.25*cos (25) + sin (25) ]*9.81*50 / [ cos (25) + 0.25*sin (25) ]

v = 8.46 m/s

6 0

3 years ago