Ask question

Ask question

All categories

4 years ago

14

Which is a characteristic of a mixture? Its components retain their properties. It can only be separated using electricity. It i

s the result of a chemical a reaction.

2 answers:

kakasveta [241]4 years ago

6 0

The first answer choice is correct

kifflom [539]4 years ago

5 0

The second one; its components retain their properties.

You might be interested in

Suppose that a 117.5 kg football player running at 6.5 m/s catches a 0.43 kg ball moving at a speed of 26.5 m/s with his feet of

Harrizon [31]

Answer:

<em>a) 6.57 m/s</em>

<em>b) 53.75 J </em>

<em>c) 6.37 m/s</em>

<em>d) -98.297 J</em>

Explanation:

mass of player = $m_{p}$ = 117.5 kg

speed of player = $v_{p}$ = 6.5 m/s

mass of ball = $m_{b}$ = 0.43 kg

velocity of ball = $v_{b}$ = 26.5 m/s

Recall that momentum of a body = mass x velocity = mv

initial momentum of the player = mv = 117.5 x 6.5 = 763.75 kg-m/s

initial momentum of the ball = mv = 0.43 x 26.5 = 11.395 kg-m/s

initial kinetic energy of the player = $\frac{1}{2} mv^{2}$ = $\frac{1}{2}$ x 117.5 x $6.5^{2}$ = 2482.187 J

a) according to conservation of momentum, the initial momentum of the system before collision must equate the final momentum of the system.

for this first case that they travel in the same direction, their momenta carry the same sign

$m_{p}$ $v_{p}$ + $m_{b}$ $v_{b}$ = ( $m_{p}$ + $m_{b}$ )v

where v is the final velocity of the player.

inserting calculated momenta of ball and player from above, we have

763.75 + 11.395 = (117.5 + 0.43)v

775.145 = 117.93v

v = 775.145/117.93 = <em>6.57 m/s</em>

b) the player's new kinetic energy = $\frac{1}{2} mv^{2}$ = $\frac{1}{2}$ x 117.5 x $6.57^{2}$ = 2535.94 J

change in kinetic energy = 2535.94 - 2482.187 = <em>53.75 J gained</em>

c) if they travel in opposite direction, equation becomes

$m_{p}$ $v_{p}$ - $m_{b}$ $v_{b}$ = ( $m_{p}$ + $m_{b}$ )v

763.75 - 11.395 = (117.5 + 0.43)v

752.355 = 117.93v

v = 752.355/117.93 =<em> 6.37 m/s</em>

d) the player's new kinetic energy = $\frac{1}{2} mv^{2}$ = $\frac{1}{2}$ x 117.5 x $6.37^{2}$ = 2383.89 J

change in kinetic energy = 2383.89 - 2482.187 = -98.297 J

that is <em>98.297 J lost</em>

3 0

4 years ago

A wave with a frequency of 840 cycles per second has what period? Please help me !!

sweet-ann [11.9K]

Answer:

0.005556

Explanation:

The period of a typical class at a high school might be 55 minutes; every 55 minutes a class cycle begins (50 minutes for class and 5 minutes for passing time means that a class begins every 55 minutes). The period for the minute hand on a clock is 3600 seconds (60 minutes); it takes the minute hand 3600 seconds to complete one cycle around the clock.

<u>How to get period from frequency</u>

The formula for the period is T = 1 / f, where "T" is period – the time it takes for one cycle to complete, and "f" is frequency.
To get period from frequency, first convert frequency from Hertz to 1/s.
Now divide 1 by the frequency. The result will be time (period) expressed in seconds.

7 0

3 years ago

Say you have a differential drive robot that has an axle length of 30cm and wheel diameter of 10cm. Find the angular velocity fo

Klio2033 [76]

Answer:

a) ω1 = 18rpm ω2 = -18rpm

b) ω1 = 102rpm ω2 = 138rpm

c) ω1 = ω2 = 3.18rpm

Explanation:

For the first case, we know that each wheel will spin in a different direction but with the same magnitude, so:

ωr = 6rpm This is the angular velocity of the robot

$\omega = \frac{\omega r * D/2}{r_{wheel}}$ where D is 30cm and rwheel is 5cm

$\omega = \frac{6 * 30/2}{5}=18rpm$ One velocity will be positive and the other will be negative:

ω1 = 18rpm ω2 = -18rpm

For part b, the formula is the same but distances change. Rcircle=100cm:

$\omega 1 = \frac{\omega r * (R_{circle} - D/2)}{r_{wheel}}$

$\omega 2 = \frac{\omega r * (R_{circle} + D/2)}{r_{wheel}}$

Replacing values, we get:

$\omega 1 = \frac{6 * (100 - 30/2)}{5}=102rpm$

$\omega 2 = \frac{\omega r * (100 + 30/2)}{5}=138rpm$

For part c, both wheels must have the same velocity:

$\omega = \frac{V_{robot}}{r_{wheel}}=20rad/min$

$\omega = 20rad/min * \frac{1rev}{2*\pi rad}=3.18rpm$

8 0

4 years ago

If a star has no measurable parallax, what can you infer?.

Leni [432]

<span>If you can't measure the parallax that means that the star is far far away, beyond all possible reach of humanity with its current technology. The closer the star is the greater the parallax, so you either get a bigger, more powerful telescope, or you just accept that it's too far away to be measured at all. Eventually the technology will develop enough to measure it.</span>

3 0

4 years ago

What do you mean by velocity ratio of a wheel and axle

IgorC [24]

Answer:

Explanation:

In wheel and axle. …with the system is the velocity ratio, or the ratio of the velocity (VF) with which the operator pulls the rope at F to the velocity at which the weight W is raised (VW). This ratio is equal to twice the radius of the large drum divided by the difference…

5 0

3 years ago