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3 years ago

14

Which statement(s) accurately describe the conditions immediately before and after the firecracker explodes:

1 answer:

lidiya [134]3 years ago

8 0

Answer:

Option C, The total momentum of the fragments is equal to the original momentum of the firecracker.

Explanation:

Kinetic energy of cracker cannot remain constant before and after explosion. It is so because in the process of burning and bursting some amount of kinetic energy is lost in the form of light and heat energy. While the total mass before and after the explosion remains constant due to which the momentum is conserved before and after the explosion

Hence, option C is correct

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Because the earth's orbit is slightly elliptical, the earth actually gets closer to the sun during part of the year. When the ea

BabaBlast [244]

Closer to the sun . . . orbital speed is faster.

Farther from the sun . . . orbital speed is slower.

Flag answer: Answer 13 Answer 13

5 0

2 years ago

A ball is traveling 24° above the horizontal at a speed of 12 m/s. What is the vertical component of its speed?

victus00 [196]

Answer:

4.88 m/s

Explanation:

Vertical component would be 12 * sin 24 = 4.88 m/s

Horizontal is 12 * cos 24

3 0

2 years ago

Find the electric energy density between the plates of a 225-μF parallel-plate capacitor. The potential difference between the p

PSYCHO15rus [73]

Answer:

Energy density will be 14.73 $J/m^3$

Explanation:

We have given capacitance $C=225\mu F=225\times 10^{-6}F$

Potential difference between the plates = 365 V

Plate separation d = 0.200 mm $0.2\times 10^{-3}m$

We know that there is relation between electric field and potential

$E=\frac{V}{d}$ , here E is electric field, V is potential and d is separation between the plates

So $E=\frac{V}{d}=\frac{365}{0.2\times 10^{-3}}=1825000N/C$

Energy density is given by $E=\frac{1}{2}\varepsilon _0E^2=\frac{1}{2}\times 8.85\times 10^{-12}\times (1.825\times 10^6)^2=14.73J/m^3$

5 0

3 years ago

Wooden handles on knives do not require maintenance.<br> TRUE<br> FALSE

Olenka [21]

Answer: false

Explanation:

You have to make sure it doesn’t stay wet

5 0

3 years ago

In a thunderstorm, electric charge builds up on the water droplets or ice crystals in a cloud. Thus, the charge can be considere

muminat

Answer:

$2.1\cdot 10^{21}$ electrons

Explanation:

The magnitude of the electric field outside an electrically charged sphere is given by the equation

$E=\frac{kQ}{r^2}$

where

k is the Coulomb's constant

Q is the charge stored on the sphere

r is the distance (from the centre of the sphere) at which the field is calculated

In this problem, the cloud is assumed to be a charged sphere, so we have:

$E_b=3.00\cdot 10^6 N/C$ is the maximum electric field strength tolerated by the air before breakdown occurs

$r=1.00 km = 1000 m$ is the radius of the sphere

Re-arranging the equation for Q, we find the maximum charge that can be stored on the cloud:

$Q=\frac{Er^2}{k}=\frac{(3.00\cdot 10^6)(1000)^2}{9\cdot 10^9}=333.3 C$

Assuming that the cloud is negatively charged, then

$Q=-333.3 C$

And since the charge of one electron is

$e=-1.6\cdot 10^{-19}C$

The number of excess electrons on the cloud is

$N=\frac{Q}{e}=\frac{-333.3}{-1.6\cdot 10^{-19}}=2.1\cdot 10^{21}$

5 0

3 years ago