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4 years ago

11

A rolling ball will eventually stop rolling. Which describes one reason why this happens? The ball eventually loses its energy.

Friction converts some of the energy into heat energy. Friction converts some of the energy into kinetic energy.

1 answer:

eduard4 years ago

5 0

The ball will eventually loses its energy.

You might be interested in

Salmon often jump waterfalls to reach their breeding grounds starting downstream, 2.9 meters away from a waterfall .436 meters i

nikklg [1K]

The minimum speed must a Salmon jumping with to leave the water

to continue upstream is 5.79 m/s

Explanation:

At first let us find the two component of the jumping velocity of the fish

1. Horizontal component $u_{x}$ = u cosФ

2. Vertical component $u_{y}$ = u sinФ

where u is the initial velocity and Ф is the angle between the horizontal

and the initial velocity u

→ Ф = 44.7°

→ $u_{x}$ = u cos(44.7)

→ $u_{y}$ = u sin(44.7)

The horizontal distance x is 2.9 meters away from a waterfall

The vertical distance y is 0.436 meters

3. The horizontal distance x = $u_{x}$ t

4. The vertical distance y = $u_{y}$ t + $\frac{1}{2}$ gt²

where g is the acceleration of gravity

→ x = u cos(44.7) t

→ x = 2.9 meters

→ 2.9 = u cos(44.7) t

Divided both sides by u cos(44.7)

→ t = $\frac{2.9}{ucos(44.7)}$ ⇒ (1)

→ y = u sin(44.7) t + $\frac{1}{2}$ gt²

→ y = 0.436 meters , g = -9.81 m/s²

→ 0.436 = u sin(44.7) t - 4.905 t² ⇒ (t)

Substitute (1) in (2) to make the equation of u only

→ 0.436 = u sin(44.7)( $\frac{2.9}{ucos(44.7)}$ ) - 4.905 ( $\frac{2.9}{ucos(44.7)}$ )²

→ 0.436 = 2.9 ( $\frac{sin(44.7)}{cos(44.7)}$ - $\frac{41.25105}{u^{2}[cos(44.7)]^{2}}$

→ 0.436 = 2.8698 - $\frac{81.4671}{u^{2} }$

Subtract 2.8698 from both sides

→ -2.4338 = - $\frac{81.4671}{u^{2} }$

Multiply both sides by -1

→ 2.4338 = $\frac{81.4671}{u^{2} }$

By using cross multiplication

∴ 2.4338 u² = 81.4671

Divide both sides by 2.4338

→ u² = 33.4732

Take √ for both sides

→ u = 5.79 m/s

<em>The minimum speed must a Salmon jumping with to leave the water</em>

<em>to continue upstream is 5.79 m/s </em>

Learn more:

You can learn more about the equation of trajectory of the projectile in brainly.com/question/2814900

brainly.com/question/5531630

#LearnwithBrainly

4 0

3 years ago

A rock is thrown from the edge of the top of a 51 m tall building at some unknown angle above the horizontal. The rock strikes t

Xelga [282]

Answer:

The speed of projection is 34 m/s.

Explanation:

Height of building, h = 51 m

horizontal distance, d = 74 m

time, t = 8 s

Let the angle is A and the speed is u.

d = u cos A x t

74 = u cos A x 8

u cos A = 9.25 .... (1)

Use second equation of motion

$h = u sin A t - 0.5 gt^2\\\\-51 = u sinA \times 8 - 0.5\times 9.8\times8\times 8\\\\u sin A = 32.8 .... (2)$

Squaring and adding both the equations

$u^2 = 9.25^2 + 32.8^2 \\\\u = 34 m/s$

8 0

3 years ago

At what value of angle between two vectors will the resultant of the two vectors be maximum?

yan [13]

The resultant is maximum when the angle between the two vectors is zero

Explanation:

The formula to calculate the resultant of two vectors A, B is the following:

$R=\sqrt{A^2+B^2+2ABcos \theta}$

where

A is the magnitude of vector A

B is the magnitude of vector B

$\theta$ is the angle between the directions of A and B

This formula can be derived by applying the parallelogram law.

From the formula, we observe that:

- When $\theta=0^{\circ}$ (vectors A and B parallel), $cos \theta = 1$ . so the resultant becomes simply

$R=\sqrt{A^2+B^2 + 2AB}=\sqrt{(A+B)^2}=A+B$

- When $\theta = 90^{\circ}$ (vectors A and B perpendicular), $cos \theta = 0$ , so the resultant becomes

$R=\sqrt{A^2+B^2}$

- When $\theta=180^{\circ}$ (vectors A and B anti-parallel), $cos \theta = -1$ , so the resultant becomes

$R=\sqrt{A^2+B^2 - 2AB}=\sqrt{(A-B)^2}=|A-B|$

By looking at the three cases and at the formula, we see that the maximum value of the resultant is when the angle between the two vectors is zero, since in that case the resultant is simply obtained by adding the magnitudes of the two vectors.

Learn more about vector addition:

brainly.com/question/4945130

brainly.com/question/5892298

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3 0

3 years ago

pakka acquires a velocity of 72 km per hour in 10 seconds starting from rest find a ) the acceleration b)the average velocity c)

nadezda [96]

Acceleration equals 24 km/s
Average equals 396km/s

8 0

4 years ago

4. A meter has a resistance of 100 Ω and gives a full scale deflection when it carries a current of 25 μA. (a) What resistor, Rx

frez [133]

Answer:

A=50mΩ

B≅50mΩ

Explanation:

A) To answer this question we have to use the Current Divider Rule. that rule says:

$Ix=.\frac{Req}{Rx} *Itotal$ (1)

Itotal represents the new maximun current, 50mA, Ix is the current going through the 100 ohms resistor, and Req. is the equivalent resitor.

We now have a set of two resistor in parallel, so:

$Req.=\frac{1}{\frac{1}{R1}+\frac{1}{R2} }$ (2)

where R1 is the resitor we have to calculate, and R2 is the 100 ohms resistor (25 uA).

substituting and rearranging (2)

$Req.=\frac{ 100*R1}{R1+100}$ (3)

Now substituting (3) in (1).

$25*10^{-6} =\frac{\frac{ 100*R1}{R1+100}}{100} *50*10^{-3}$

solving this, The value of R1 is: 50mΩ

This value of R1 will guaranty that the ammeter full reflection willl be at 50mA.

Given that R2 (100ohm) it too much bigger than 50mΩ, the equivalent resistor will tend to 50mΩ

If you substitude this values on (2) Req. will be 49.97 mΩ.

7 0

3 years ago