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3 years ago

The statement, "Energy can neither be created nor destroyed, but can change from one form to another," is what law?

1 answer:

3 0

<span>In chemical reaction, atoms always are rearranged. They are never destroyed or created because it would contradict the law of conservation of energy. The law of conservation of energy states that energy can neither be created nor destroyed, but can change from one form to another. Also it cannot be neutralized. Resulting in one cannot be part of a chemical reaction. An example of this is the reaction HCl + NaOH -> NaCl + H2O. the reactants and products are not created, they are just formed into another substance.</span>

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A loop of wire is carrying current of 2 A . The radius of the loop is 0.4 m. What is the magnetic field at a distance 0.09 m alo

HACTEHA [7]

Answer:

$B=2.91\ \mu T$

Explanation:

Given that,

The current in the loop, I = 2 A

The radius of the loop, r = 0.4 m

We need to find the magnetic field at a distance 0.09 m along the axis and above the center of the loop. The formula for the magnetic field at some distance is given as follows :

$B=\dfrac{\mu_o}{4\pi }\dfrac{2\pi r^2 I}{(r^2+d^2)^{3/2}}$

Put all the values,

$B=10^{-7}\times \dfrac{2\pi \times 0.4^2 \times 2}{(0.4^2+0.09^2)^{3/2}}\\\\=2.91\times 10^{-6}\ T\\\\or\\\\B=2.91\ \mu T$

So, the required magnetic field is equal to $2.91\ \mu T$ .

3 0

3 years ago

Help please..................

Shtirlitz [24]

<h3><em>If two objects with the same charge are brought towards each other the force produced will be repulsive, it will push them apart. If two objects with opposite charges are brought towards each other the force will be attractive, it will pull them towards each other.</em></h3><h3><em>hope it helps.... thank you....</em></h3>

7 0

3 years ago

When the displacement of a mass on a spring is 12 A, what percentage of the energy is kinetic energy?

Zolol [24]

Answer:

1.44%

Explanation:

The potential energy of a spring is given by

$U=\dfrac{1}{2}kx^2$

The kinetic energy is

$E=\dfrac{1}{2}kA^2$

Now x = 12 A

Applying in the first equation

$U=\dfrac{1}{2}k(12A)^2\\\Rightarrow U=\dfrac{1}{2}k144A^2\\\Rightarrow U=144\dfrac{1}{2}kA^2\\\Rightarrow U=144E$

The percentage would be 14400%

at $x=\dfrac{1}{2}A$ (makes more sense)

$U=\dfrac{1}{2}k(\dfrac{1}{2}A)^2\\\Rightarrow U=\dfrac{1}{2}k\dfrac{1}{4}A^2\\\Rightarrow U=\dfrac{1}{4}\times \dfrac{1}{2}kA^2\\\Rightarrow U=0.25E$

The percentage is 25 % of the kinetic energy

6 0

3 years ago

Mr. Beall paddles his canoe at 8.0 m/s North in a river that flows at 6.0 m/s to the South. What is the magnitude and direction

kifflom [539]

Answer:

2 /s north

Explanation:

Given that,

Velocity due North is 8 m/s and due south is 6 m/s

We need to find the magnitude and the direction of the resulting velocity.

Let North is positive and South is negative. When two velocities are in opposite direction, they adds up. So,

$v=8+(-6)\\\\v=2\ m/s$

It is positive. So, it is in North direction.

3 0

3 years ago

Using the solar constant, estimate the rate at which the whole Earth receives energy from the Sun. (Hint: Think about the area o

harkovskaia [24]

Answer:

1.475×10²⁴ W

Explanation:

I = Solar constant of the sun = 1362 W/m² (measured using satellites with value 1.3608 ± 0.0005 kW/m² the error is due to fact that solar output is not always constant)

r = Radius of earth = 6371 km = 6371000 m (mean radius)

A = Area of earth = (4/3)×π×r³

=(4/3)×π×6371000³ = 1.083×10²¹ m²

P = I×A

⇒P = 1362×1.083×10²¹

⇒P = 1.475×10²⁴ W

∴ Rate at which the whole Earth receives energy from the Sun is 1.475×10²⁴ W

4 0

3 years ago