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3 years ago

Which property is shown by the rails of a railway track?

Physics

1 answer:

damaskus [11]3 years ago

6 0

Parallelism is a property shown by the rails of a railway track.

Option B

Explanation:

Parallelism is the property of the lines which do not meet in a plane, those lines which "do not intersect or touch each other" are parallel to each other.

In the given example, railway lines of railway track are said to be parallel since they are at an equal distance to each point so that the wheels of the train be on track. Since these railway lines do not meet each other even at infinity, they are said to be parallel.

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A jogger runs 5.0 km on a straight trail at an angle of 60° south of west. What is the southern component of the run rounded to

geniusboy [140]

Answer:

4.3 km

Explanation:

5 0

2 years ago

The greatest speed with which an athlete can jump vertically is around 5 m/sec. Determine the speed at which Earth would move do

katrin2010 [14]

Answer:

Approximately $2.0 \times 10^{-23}\; \rm m \cdot s^{-1}$ if that athlete jumped up at $1.8\; \rm m \cdot s^{-1}$ . (Assuming that $g = 9.81\; \rm m\cdot s^{-1}$ .)

Explanation:

The momentum $p$ of an object is the product of its mass $m$ and its velocity $v$ . That is: $p = m \cdot v$ .

Before the jump, the speed of the athlete and the earth would be zero (relative to each other.) That is: $v(\text{athlete, before}) = 0$ and $v(\text{earth, before}) = 0$ . Therefore:

$\begin{aligned}& p(\text{athlete, before}) = 0\end{aligned}$ and $p(\text{earth, before}) = 0$ .

Assume that there is no force from outside of the earth (and the athlete) acting on the two. Momentum should be conserved at the instant that the athlete jumped up from the earth.

Before the jump, the sum of the momentum of the athlete and the earth was zero. Because momentum is conserved, the sum of the momentum of the two objects after the jump should also be zero. That is:

$\begin{aligned}& p(\text{athlete, after}) + p(\text{earth, after}) \\ & =p(\text{athlete, before}) + p(\text{earth, before}) \\ &= 0\end{aligned}$ .

Therefore:

$p(\text{athelete, after}) = - p(\text{earth, after})$ .

$\begin{aligned}& m(\text{athlete}) \cdot v(\text{athelete, after}) \\ &= - m(\text{earth}) \cdot v(\text{earth, after})\end{aligned}$ .

Rewrite this equation to find an expression for $v(\text{earth, after})$ , the speed of the earth after the jump:

$\begin{aligned} &v(\text{earth, after}) \\ &= -\frac{m(\text{athlete}) \cdot v(\text{athlete, after})}{m(\text{earth})} \end{aligned}$ .

The mass of the athlete needs to be calculated from the weight of this athlete. Assume that the gravitational field strength is $g = 9.81\; \rm N \cdot kg^{-1}$ .

$\begin{aligned}& m(\text{athlete}) = \frac{664\; \rm N}{9.81\; \rm N \cdot kg^{-1}} \approx 67.686\; \rm N\end{aligned}$ .

Calculate $v(\text{earth, after})$ using $m(\text{earth})$ and $v(\text{athlete, after})$ values from the question:

$\begin{aligned} &v(\text{earth, after}) \\ &= -\frac{m(\text{athlete}) \cdot v(\text{athlete, after})}{m(\text{earth})} \\ &\approx -2.0 \times 10^{-23}\; \rm m \cdot s^{-1}\end{aligned}$ .

The negative sign suggests that the earth would move downwards after the jump. The speed of the motion would be approximately $2.0 \times 10^{-23}\; \rm m \cdot s^{-1}$ .

3 0

3 years ago

What is a topgraphic map?

Anuta_ua [19.1K]

Answer:

A topographic map is a map that indicates the features of the land's surface, such as mountains, hills, and valleys. This is usually done with wavy lines that represent the curves and elevation of the land.

8 0

3 years ago

You take a Frisbee to the top of the Washington Monument and send it sailing along horizontally at a speed of 5 m/s from the ver

Dominik [7]

This question can be solved with the help of the equations of motion.

A) The Frisbee will remain in the air for "5.87 s".

B) The frisbee will go "29.4 m" down the range.

To calculate the time, the frisbee will remain in the air, we will use the second equation of motion, for the vertical motion.

$h = v_it+\frac{1}{2}gt^2\\\\$

where,

h = height = 169.2 m

vi = initial velocity's vertical component = 0 m/s

g = acceleration due to gravity = 9.81 m/s²

t = time = ?

Therefore,

$169.2\ m = (0\ m/s)(t)+\frac{1}{2}(9.81\ m/s^2)t^2\\\\t = \sqrt{\frac{(169.2\ m)(2)}{9.81\ m/s^2}}$

t = 5.87 s

Now, we will calculate the horizontal range by applying the equation for constant motion. Because the velocity in the horizontal direction will remain constant due to no air resistance

s = vt

where,

s = horizontal range = ?

v= initial velocity's horizontal component = 5 m/s

t = time = 5.87 s

Therefore,

s = (5 m/s)(5.87 s)

s = 29.4 m

Learn more about equations of motion here:

brainly.com/question/9772550?referrer=searchResults

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3 years ago

The material that is most difficult to recycle is

juin [17]

The material that is most difficult to recycle is aluminum.

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3 years ago

Read 2 more answers