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3 years ago

In terms of thermal expansion, why is water unusual?

1 answer:

6 0

Water is unusual in terms of thermal expansion because other substances are denser in solid form and less dense in liquid form, while water is denser in liquid form and less dense in solid form. Water bonds in such a way that molecules are help farther apart in solid form than in liquid form.

You might be interested in

How much of the electro magnetic spectrum is visible to us

Rudiy27

Answer:

The entire rainbow of radiation observable to the human eye only makes up a tiny portion of the electromagnetic spectrum – about 0.0035 percent. This range of wavelengths is known as visible light.

Explanation:

Please Mark me brainliest

3 0

3 years ago

A student attempts to spin a rubber stopper(m=0.5kg) in a horizontal circle with a radius of 0.75m.If the stopper completes 2.5

Nastasia [14]

Explanation:

a) ac = r(omega)^2

where omega = 2.5 rev/s

r = 0.75 m

We need to convert rev/s first into rad/s:

2.5 rev/s × (2pi rad/rev) = 5pi rad/s = omega

Therefore, the centripetal acceleration ac is

ac = (0.75 m)×(5pi rad/s)^2

= 185 m/s^2

b) Fc = mac

= (0.5 kg)(185 m/s^2)

= 92.5 N

5 0

3 years ago

A Circular loop in the plane of a paper lies in a 0.65 TT magnetic field pointing into the paper. The loop's diameter changes fr

Kobotan [32]

Answer:

Explanation:

magnetic filed, B = 0.65 T

initial diameter, d = 17.5 cm

final diameter, d' = 6.6 cm

time, t = 0.48 s

(a) According to Lenz's law, the direction of induced current is clockwise.

(b) Let e is the induced emf.

initial area, A = π r² = 3.14 x 0.0875 x 0.0875 = 0.024 m²

final area, A' = π r'² = 3.14 x 0.033 x 0.033 = 0.00342 m²

change in area, ΔA = A - A' = 0.024 - 0.00342 = 0.02058 m²

The magnitude of induced emf is given by

$e=\frac{d\phi }{dt}$

$e=B\frac{\Delta A }{dt}$

e = 0.65 x 0.02058 / 0.48

e = 0.028 V

i = e / R

i = 0.028 / 2.5

i = 0.011 A

6 0

3 years ago

Emily takes a trip, driving with a constant velocity of 87.5 km/h to the north except for a 22 min rest stop. If Emily's average

rjkz [21]

<h2>Answer:</h2>

2.63 hours

<h2>Explanation:</h2>

First we have to read carefully the problem, It start telling us that Emily was driving with average velocity of 87.5 km/h to the north. Velocity is a physical variable that is definded in terms of :

Speed of the object (87.5 km/h)

Direction of the object (north)

Them the problem says that Emily's trip has an average velocity of 76.8 km/h to the north because she made a rest stop for 22 minutes.

Now you can ask yourself: If Emily was driving at 87.5 km/h, why the average speed of the trip was 76.8 km/h?

we need to see how speed is defined:

$Speed=\frac{distance}{time} =\frac{x}{y}$

***Note 1:

Distance will be called as "x" and units will be kilometers(km)

Time will be called as "y" and units will be hours(h)

So, 87.5 km/h would be the average speed for a distance "x" and a time "y" without stops. But Emily made a stop that took 22 minutes. For the same distance Emily's trip took more time and time is in the denominator. If our numerator is constant and our denominator gets higher, the final result will be lower

Now, we have the follow expressions:

$87.5=\frac{x}{y}~~(1) \\76.8=\frac{x}{y+\frac{22}{60}}~~(2)$

***Note 2:

we need to convert 22 minutes to hours. 1 hour= 60 minutes, so we need to apply the follow covert factor:

$y(hours)=y(minutes)*\frac{1(hour)}{60(minutes)}$

The problem aks us about how long does the trip take, it means that we have to find y.

We have two variables (x and y), and we have two equationts. We know that x have the same value for both problems (Because both average speeds have the same distance), so we can solve both equations for x and made equal each other

$87.5*y=x~(3)\\76.8*(y+\frac{22}{60})=x~(4)$

$87.5*y=76.8*(y+\frac{22}{60})~(5)$

We have to expand (5) and then we have to solve for y

$87.5*y=76.8*y+76.8*\frac{22}{60}~~(6)\\87.5*y-76.8*y=76.8*\frac{22}{60}~~(7)\\10.7*y=76.8*\frac{22}{60}~~(8)\\y=\frac{76.8}{10.7}*\frac{22}{60}(hours)~~(9)\\y=2.63(hours)~~(10)$

3 0

3 years ago

A devout halloweener not only dressed as an astronaut, but travelled to the moon for the full experience. The astronaut jumps on

nikdorinn [45]

Answer:

2.78 m

Explanation:

At the peak, the velocity is 0.

Given:

a = -1.6 m/s²

v₀ = 2.98 m/s

v = 0 m/s

x₀ = 0 m

Find:

v² = v₀² + 2a(x - x₀)

(0 m/s)² = (2.98 m/s)² + 2(-1.6 m/s²) (x - 0 m)

x = 2.775 m

Rounded to 3 sig-figs, the astronaut halloweener reaches a maximum height of 2.78 meters.

5 0

3 years ago