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3 years ago

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1. A tourist accidentally drops a camera from a 40.0 m high bridge and it falls for 2.85 seconds. If g = 9.81 m/s2 and air resis

tance are disregarded, what is the speed of the camera as it hits the water?

1 answer:

attashe74 [19]3 years ago

6 0

Answer:

28 m/s

Explanation:

v(final)^2=v(initial)^2+2a(delta y)

=sqrt(2*-9.8 m/s^2*-40)

28 m/s

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What would the kinetic energy and potential energy be with the snowboarder, before during and after a jump?

Reika [66]

Answer: Before the jump, the snowboarder would carry potential energy.

During the jump he will carry kinetic energy.

And after the jump, assuming hes at a full stop, he will carry potential energy once again.

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3 years ago

A baseball player leads off the game and hits a long home run. The ball leaves the bat at an angle of 70.0 from the horizontal w

professor190 [17]

Answer: 211.059 m

Explanation:

We have the following data:

$\theta=70\°$ The angle at which the ball leaves the bat

$V_{o}=55 m/s$ The initial velocity of the ball

$g=-9.8 m/s^{2}$ The acceleration due gravity

We need to find how far (horizontally) the ball travels in the air: $x$

Firstly we need to know this velocity has two components:

<u>Horizontally:</u>

$V_{ox}=V_{o}cos \theta$ (1)

$V_{ox}=55 m/s cos(70\°)=18.811 m/s$ (2)

<u>Vertically:</u>

$V_{oy}=V_{o}sin \theta$ (3)

$V_{oy}=55 m/s sin(70\°)=51.683 m/s$ (4)

On the other hand, when we talk about parabolic movement (as in this situation) the ball reaches its maximum height just in the middle of this parabola, when $V=0$ and the time $t$ is half the time it takes the complete parabolic path.

So, if we use the following equation, we will find $t$ :

$V=V_{o}+gt=0$ (5)

Isolating $t$ :

$t=\frac{-V_{o}}{g}$ (6)

$t=\frac{-55 m/s}{-9.8 m/s^{2}}$ (7)

$t=5.61 s$ (8)

Now that we have the time it takes to the ball to travel half of is path, we can find the total time $T$ it takes the complete parabolic path, which is twice $t$ :

$T=2t=2(5.61 s)=11.22 s$ (9)

With this result in mind, we can finally calculate how far the ball travels in the air:

$x=V_{ox}T$ (10)

Substituting (2) and (9) in (10):

$x=(18.811 m/s)(11.22 s)$ (11)

Finally:

$x=211.059 m$

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adoni [48]

The uniform microwave radiation remaining from the Big Bang.

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3 years ago

A string of 26 identical Christmas tree lights are connected in series to a 120 V source. The string dissipates 73 W. What is th

spin [16.1K]

To solve this problem we will apply the concepts related to Ohm's law and Electric Power. By Ohm's law we know that resistance is equivalent to,

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Here,

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While the power is equivalent to the product between the current and the voltage, thus solving for the current we have,

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Applying Ohm's law

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On a straight, level, two-lane road, two cars moving in opposite directions approach and pass each other. Car A is in the eastbo

ludmilkaskok [199]

Answer:

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42 m/s, positive direction (to the east).

b) The relative velocity of Car B as seen by the drive of Car A is:

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42 m/s, negative direction (to the west).

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3 years ago