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svp [43]
3 years ago
6

Which idea did Ptolemy's model use to explain why the planets appeared to move backward as they moved in their orbits? The plane

ts spun in epicycles. The planets rotated on their axes. The planets revolved around the Sun. The planets were made of different materials.
Physics
2 answers:
aksik [14]3 years ago
8 0

Answer:A

Explanation:

ruslelena [56]3 years ago
3 0

Answer:

The planets spun in epicycles.

Explanation:

The planets were not simply attached to a mystical sphere (“deferent”) but they were actually attached to a mini-sphere (“epicycle”) which rotated on the larger one.

You might be interested in
How do magnet effect materials that are not magnets
givi [52]

Answer: Magnetic metals & non-magnetic metals both play an important role in engineering. Magnetism is the basis for many applications. At the same time, this property may also be unwanted in certain circumstances.

Therefore, it is important to know which metals are magnetic and which ones are not.

Explanation:

3 0
3 years ago
Mass of object is 50g moves in a circular path of radius 10cm find work done
topjm [15]

Answer:

Work done = 0.3142 Nm

Explanation:

Mass of Object is 50 g

Circular path of radius is 10 cm ⇒ 0.1 m

Work done = Force × Distance = ?

*Distance moved (circular path) ⇒ Circumference of the circular path

2πr = 2 × 3.142 × 0.1 ⇒ 0.6284 m

*Force that is enough to move a 50 g must be equal or more than its weight.

therefore convert 50 grams to newton = 0.5 N

Recall that; work done is force times distance

∴ 0.5 N × 0.6284 m

Work done = 0.3142 Nm

3 0
3 years ago
Vivian went on a bicycle trip through Germany with her family. One afternoon, she rode her bicycle along a long flat road at a c
natima [27]

d = distance traveled by her on her bicycle on a long flat road = 24 kilometer

t = time taken by her to travel distance "d" on her bicycle on a long flat road = 1.2 hours

v = average speed of vivian = ?

we know that average speed is given as

v = d/t

inserting the values in the above formula

v = 24 kilometer / 1.2 hour

v = 20 kilometer/hour


hence the correct choice is

C) 20 km/h



8 0
3 years ago
A car travels at a steady 40.0 m/s around a horizontal curve of radius 200 m. What is the minimumcoefficient of static friction
zhenek [66]

Answer:

c. 0.816

Explanation:

Let the mass of car be 'm' and coefficient of static friction be 'μ'.

Given:

Speed of the car (v) = 40.0 m/s

Radius of the curve (R) = 200 m

As the car is making a circular turn, the force acting on it is centripetal force which is given as:

Centripetal force is, F_c=\frac{mv^2}{R}

The frictional force is given as:

Friction = Normal force × Coefficient of static friction

f=\mu N

As there is no vertical motion, therefore, N=mg. So,

f=\mu mg

Now, the centripetal force is provided by the frictional force. Therefore,

Frictional force = Centripetal force

f=F_c\\\\\mu mg=\frac{mv^2}{R}\\\\\mu=\frac{v^2}{Rg}

Plug in the given values and solve for 'μ'. This gives,

\mu = \frac{(40\ m/s)^2}{200\ m\times 9.8\ m/s^2}\\\\\mu=\frac{1600\ m^2/s^2}{1960\ m^2/s^2}\\\\\mu=0.816

Therefore, option (c) is correct.

7 0
3 years ago
When looking at the chemical symbol, the charge of the ion is displayed as the
Black_prince [1.1K]

Answer:

superscript

Explanation:

When looking at the chemical symbol, the charge of the ion is displayed as the Superscript. This is because the charge of ions is usually written up on the chemical symbol while the atom/molecule is usually written down the chemical symbol. The superscript refers to what is written up on the formula while the subscript is written down on the formula.

An example is H2O . The 2 present represents two molecule of oxygen and its written as the subscript while Fe2+ in which the 2+ is written up is known as the superscript.

6 0
3 years ago
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