Most ozone is found in a region of Earth’s

How much heat is needed to raise the temperature of 5g of water by 20oC?

Ratling [72]

Required Heat = Q

Q = Mass * specific heat of water * change in temp.

Q = 5g * 1g/cal*degC * 20degC

Q = 100 cal of heat is required

To convert calories to Joules,
1 cal = 4.184 Joules

100cal = 418.4 J of heat is needed

5 0

3 years ago

Two charged spheres are 20 cm apart and exert an attractive force of 8 x 10-9 n on each other. What will the force of attraction

Pavel [41]

Answer:

$3.2\cdot 10^{-8} N$

Explanation:

The inital electrostatic force between the two spheres is given by:

$F=k\frac{q_1 q_2}{r^2}$

where

$F=8\cdot 10^{-9} N$ is the initial force

k is the Coulomb's constant

q1 and q2 are the charges on the two spheres

r is the distance between the two spheres

The problem tells us that the two spheres are moved from a distance of r=20 cm to a distance of r'=10 cm. So we have

$r'=\frac{r}{2}$

Therefore, the new electrostatic force will be

$F'=k\frac{q_1 q_2}{(r')^2}=k\frac{q_1 q_2}{(r/2)^2}=4k\frac{q_1 q_2}{r^2}=4F$

So the force has increased by a factor 4. By using $F=8\cdot 10^{-9} N$ , we find

$F'=4(8\cdot 10^{-9} N)=3.2\cdot 10^{-8} N$

6 0

3 years ago

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arr

Natalija [7]

Answer:

a) F = 680 N, b) W = 215 .4 J , c) F = 1278.4 N

Explanation:

a) Hooke's law is

F = k x

To find the displacement (x) let's use the elastic energy equation

$K_{e}$ = ½ k x²

k = 2 $K_{e}$ / x²

k = 2 85.0 / 0.250²

k = 2720 N / m

We replace and look for elastic force

F = 2720 0.250

F = 680 N

b) The definition of work is

W = ΔEm

W = $K_{ef}$ - $K_{eo}$

W = ½ k ( $x_{f}$ ² - x₀²)

The final distance

$x_{f}$ = 0.250 +0.220

$x_{f}$ = 0.4750 m

We calculate the work

W = ½ 2720 (0.47² - 0.25²)

W = 215 .4 J

We calculate the strength

F = k $x_{f}$

F = 2720 0.470

F = 1278.4 N

6 0

3 years ago

A rock is thrown at an angle of 30 degrees above the horizontal with initial velocity 15m/s what is the displacement when the ro

Delvig [45]

The displacement of the rock will be the same as the total horizontal distance traveled. Here the rock's horizontal position is given by

$x=\left(15\,\dfrac{\mathrm m}{\mathrm s}\right)\cos30^\circ\,t$

so to find the horizontal distance it traversed, we need to know the time it took for the rock to return to the ground. We use the rock's vertical position over time to figure that out:

$y=\left(15\,\dfrac{\mathrm m}{\mathrm s}\right)\sin30^\circ\,t-\dfrac g2t^2=0$

where $g=9.8\,\dfrac{\mathrm m}{\mathrm s^2}$ is the acceleration due to gravity. Then we find that $t\approx1.5\,\mathrm s$ , at which point we find $x\approx20\,\mathrm m$ .

6 0

3 years ago

By using moving ________________ and _________________ wire together, electric

MrMuchimi

Answer:

By using moving magnet and a copper wire together, electric generators creates electricity. Electricity generators essentially convert kinetic energy (the energy of motion) into electrical energy.

5 0

3 years ago

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