GIVING BRAINLY, FOLLOW, STARS AND POINTS

In August 2011, the Juno spacecraft was launched from Earth with the mission of orbiting Jupiter in 2016. The closest distance b

Vikentia [17]

(a) 8927 mi/h

In order to calculate the average speed, we need to convert the time (t=5.0 y) into hours first. In 1 year, we have 365 days, each day consisting of 24 hours, so the time taken is:

$t=(5.0 y)(365 d/y)(24 h/d)=43,800 h$

The distance covered by the spacecraft is

$d=391 mil. mi = 391\cdot 10^6 mi$

Therefore, the average speed is just the ratio between the distance covered and the time taken:

$v=\frac{d}{t}=\frac{391\cdot 10^6 mi}{43,800 h}=8,927 mi/h$

(b) 35 minutes (2097 seconds)

The transmitted signals (which is a radio wave, which is an electromagnetic wave) travels back to the Earth at the speed of light:

$c=3.0\cdot 10^8 m/s$

Since 1 miles = 1609 metres, the distance covered by the signal is

$d=391\cdot 10^6 mi \cdot (1609 m/mi)=6.29\cdot 10^{11} m$

So, the time taken by the signal will be

$t=\frac{d}{v}=\frac{6.29\cdot 10^{11} m}{3.0\cdot 10^8 m/s}=2097 s$

And since 1 minute = 60 sec, the time taken is

$t=2097 s \cdot \frac{1}{60 s/min}\sim 35 min$

7 0

3 years ago

A 30 N rock falls from a 40 m cliff. At what point during its fall are its

vaieri [72.5K]

Answer:

<em>Both energies are equal when the rock has fallen 20 m or equivalently when it is at a height of 20 m.</em>

Explanation:

<u>Potential and Kinetic Energy</u>

The gravitational potential energy is the energy an object has due to its height above the ground. The formula is

$U=mgh$

Where:

m = mass of the object

g = acceleration of gravity (9.8~m/s^2)

h = height

Note we can also use the object's weight W=mg into the formula:

$U=Wh$

The kinetic energy is the energy an object has due to its speed:

$\displaystyle K=\frac{1}{2}mv^2$

Where v is the object's speed.

Initially, the object has no kinetic energy because it's assumed at rest.

The W=30 N rock falls from a height of h=40 m, thus:

$U=30*40=1,200 J$

Since the sum of the kinetic and potential energies is constant:

U' + K' = 1,200 J

Here, U' and K' are the energies at any point of the motion. Since both must be the same:

U' = K' = 600 J

U'=Wh'=600

Solving for h':

$\displaystyle h'=\frac{600}{W}=\frac{600}{30}=20~m$

Both energies are equal when the rock has fallen 20 m or equivalently when it is at a height of 20 m.

3 0

3 years ago

A man pushes a box of 40kg up incline of 15°, if the man applies a horizontal force of 200N and the box moves up the plane a dis

Tatiana [17]

20 m is the correct answer

5 0

4 years ago

For a home sound system, two small speakers are located so that one is 52 cm closer to the listener than the other. What is the

alekssr [168]

You'll get destructive interference if both waves are the same frequency but the peaks of one wave overlap the troughs of the other wave.

That can only happen if one wave has to travel (1/2 wavelength) farther than the other one to reach your ears. So we want to find the lowest frequency for which 52 cm is 1/2 of a wavelength ... the wavelength is 104 cm.

Frequency = (speed) / (wavelength)

Frequency = (344 m/s) / (104 cm)

Frequency = (344 m/s) / (1.04 meter)

Frequency = (344 / 1.04) per second

Frequency = 330.8 Hz .

7 0

3 years ago

If an element has 2 valence electrons, how many dots will be in the elements dot diagram?

antiseptic1488 [7]

Well since we're doing the Lewis dot diagram do you know which element on the table that it is?

6 0

3 years ago

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