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4 years ago

Why do the densities of most substances decrease with an increase in temperature?

1 answer:

7 0

Because density is related to activity of particles, the higher the activity level (the faster they're moving, and distance between them) the less dense they are. for example, H2O in a solid the particles are close together with minimum movement and it exists as ice, but when heat is applied the particles become more active and move more decreasing the density becoming liquid water, then when excessive heat is applied the same occurs and it becomes gas steam

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A 15-µF capacitor and a 25-µF capacitor are connected in parallel, and charged to a potential difference of 60 V. How much energ

Alborosie

Answer:

Energy stored, E = 0.072 J

Explanation:

Given that,

Capacitance, $C_1=15\ \mu F$

Capacitance, $C_2=25\ \mu F$

These two capacitor are connected in parallel, and charged to a potential difference of, V = 60 volts

We know that in parallel combination of capacitor, the equivalent capacitance is given by :

$C=C_1+C_2\\\\C=(15+25)\ \mu F\\\\C=40\times 10^{-6}\ F$

The energy stored in the capacitor is given by :

$E=\dfrac{1}{2}CV^2\\\\E=\dfrac{1}{2}\times 40\times 10^{-6}\times (60)^2\\\\E=0.072\ J$

So, the energy stored in the capacitor in this capacitor combination is 0.072 J.

4 0

3 years ago

The density of atmosphere (measured in kilograms/meter3) on a certain planet is found to decrease as altitude increases (as meas

mixer [17]

I know that the relationship between altitude and atmospheric density is that the higher the altitude, the lesser the density, and the lower the altitude the higher the density. Lower density float to the top, and higher density is 'heavy' so it comes down

6 0

3 years ago

I need help ASAP....

Svetradugi [14.3K]

Answer:

Meters

Explanation:"How FAR did the athlete run?"

Also it talked about meters

5 0

4 years ago

What is the role of MnO2 in a dry cell?

padilas [110]

Answer:MNO2 is a depolarizer in a dry cell

Explanation:

MNO2 is depolarizer in a dry cell. depolarizers are chemicals used to reduce or prevent polarization of cells

7 0

3 years ago

Two blocks with masses 1 and 2 are connected by a massless string that passes over a massless pulley as shown. 1 has a mass of 2

Bess [88]

Answer:

The acceleration of $M_2$ is $a = 0.7156 m/s^2$

Explanation:

From the question we are told that

The mass of first block is $M_1 = 2.25 \ kg$

The angle of inclination of first block is $\theta _1 = 43.5^o$

The coefficient of kinetic friction of the first block is $\mu_1 = 0.205$

The mass of the second block is $M_2 = 5.45 \ kg$

The angle of inclination of the second block is $\theta _2 = 32.5^o$

The coefficient of kinetic friction of the second block is $\mu _2 = 0.105$

The acceleration of $M_1 \ and\ M_2$ are same

The force acting on the mass $M_1$ is mathematically represented as

$F_1 = T - M_1gsin \theta_1 - \mu_1 M_1 g cos\theta_1$

=> $M_1 a = T - M_1gsin \theta_1 - \mu_1 M_1 g cos\theta_1$

Where T is the tension on the rope

The force acting on the mass $M_2$ is mathematically represented as

$F_2 = M_2gsin \theta_2 - T -\mu_2 M_2 g cos\theta_2$

$M_2 a = M_2gsin \theta_2 - T -\mu_2 M_2 g cos\theta_2$

At equilibrium

$F_1 = F_2$

$T - M_1gsin \theta_1 - \mu_1 M_1 g cos\theta_1 =M_2gsin \theta_2 - T -\mu_2 M_2 g cos\theta_2$

making a the subject of the formula

$a = \frac{M_2 g sin \theta_2 - M_1 g sin \theta_1 - \mu_1 M_1g cos \theta - \mu_2 M_2 g cos \theta_2 }{M_1 +M_2}$

substituting values $a = \frac{(5.45) (9.8) sin (32.5) - (2.25) (9.8) sin (43.5) - (0.205)*(2.25) *9.8cos (43.5) - (0.105)*(5.45) *(9.8) cos(32.5) }{2.25 +5.45}$

=> $a = 0.7156 m/s^2$

3 0

4 years ago