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3 years ago

In Kepler's model of the solar system, the planets move around the Sun in _________ orbits.

Physics

1 answer:

cestrela7 [59]3 years ago

3 0

B. elliptical.

The planets move in elliptical orbits round the Sun.

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A helicopter flies with an air speed of 175 km/h, heading south. The wind is blowing at 85 km/h to the east relative to the grou

spayn [35]

Answer:

154° at 195 km/h

Explanation:

The helicopter is moving south at 175 km/h, relative to the wind.

But the wind is moving east at 85 km/h, relative to the ground.

This means that the helicopter is moving south east relative to the ground.

Every hour, the helicopter will move 175 km to the south and 85 km to the east, relative to the ground.

This means that we can determine the speed and direction of the helicopter using a right triangle and simple trigonometry.

Refer to the triangle b1.

The distance traveled by the helicopter in 1 hour is denoted by d.

d is the hypotenuse of the right triangle.

Using the Pythagorean Theorem, we can calculate d to be 195 km (rounded to 3 s. f.)

Hence the helicopter is traveling at 195 km/h relative to the ground.

To calculate the direction we use,

tan (x) = opposite/adjacent = 85/175

So the angle x is,

$x = arctan (\frac{85}{175} )$ = 25.9°

Relative to the North, the helicopter is moving at 180° - 25.9° = 154° (rounded to 3 s. f.)

8 0

2 years ago

Hold a pencil in front of your eye at a position where its blunt end just blocks out the Moon.

Valentin [98]

Answer:

$D = 3.55 \times 10^6 m$

Explanation:

Light rays coming from moon is blocked by the pencil

so as per figure we know that angle subtended by pencil and angle subtended by moon must be same

so we have

$Angle = \frac{Arc}{Radius}$

so we have

$\frac{D}{3.8 \times 10^8 m} = \frac{0.7 cm}{75 cm}$

so we have

$D = 3.55 \times 10^6 m$

4 0

3 years ago

A car has a mass of 1000 kg and accelerates at 2 m/s2. What net force is exerted on the car?

prisoha [69]

Answer:

1000N

Explanation:

Based on force=mass*acceleration, if the acceleration is constant at 2 metres per second squared, 1,000kg*2m/s^2=2,000N of force.

If the acceleration steadily increases to 2m/s^2 in 20 seconds, take the average which is 1m/s^2 therefore force=1,000N

6 0

3 years ago

a fly wheel of mass 12kg and radius 0.5m with wrapped around it.on the end of the rope is 2kg load.intially it is at rest.calcul

leva [86]

Answer:

19.6 N of torque. The 2kg load is being affected by acceleration due to gravity which is 9.8 m/s^s

Explanation:

2×9.8=19.6

6 0

2 years ago

You comb your hair and the comb becomes negatively charged. Strictly speaking, how will the mass of your hair change? A. it wil

Step2247 [10]

Answer:

C. it will not change.

Explanation:

While combing, the rubbing of the comb with the hair, transfer of electron takes place from the hair to the comb and the comb becomes negatively charged. But, this transfer of electron does not make any considerable change in the mass of the hair. This is because the mass of an electron is highly negligible. Now, neglecting the mass of an electron, the transfer of the electrons from the hair to the comb makes charging of the comb, but no loss of mass in the hair. So, the mass of hair will no change.

7 0

3 years ago