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3 years ago

Question 2 (5 points)

Physics

1 answer:

Helen [10]3 years ago

5 0

Answer: A) All matter and energy were contained inside the small point.

Explanation: The theory that all matter and energy in the universe expanded from one condensed point (this is called the big bang theory) is the generally accepted explanation of the origins of our universe. Thought increasing amounts of doubt have been cast upon this theory in the last decade.

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A uniform marble rolls down a symmetric bowl, starting from rest atthe top of the left side. The top of each side is a distanceh

Debora [2.8K]

Answer:

A. 5/7h

B. Same height

C. See attachment below

Explanation:

Find the attachment below for better understanding.

7 0

3 years ago

Question 33

pantera1 [17]

Answer:

A. The waves in the water travel faster and at a higher frequency than they travel on land.

Explanation:

The main reason why human ears can hear dolphins' vocalizations while under the water but cannot hear them well on land is because water is denser than air and air particles travel faster in denser particles.

Denser particles also ensures that the frequency of the waves move faster which in turn produces a faster and louder result.

3 0

2 years ago

A 129-kg horizontal platform is a uniform disk of radius 1.51 m and can rotate about the vertical axis through its center. A 67.

blondinia [14]

Answer:

I = 274.75 kg-m²

Explanation:

given,

mass of horizontal platform = 129 Kg

radius of the disk = 1.51 m

mass of the person(m_p) = 67.5 Kg

standing at distance(r_p) = 1.09 m

mass of dog(m_d) = 25.3 Kg

sitting near the person(r_d) = 1.37 m from center

moment of inertia = ?

Moment of inertia of disc = $\dfrac{1}{2}MR^2$

Moment of inertia of the system

$I = MOI\ of\ disk + m_p r_p^2 + m_d r_d^2$

$I = \dfrac{1}{2}MR^2 + m_p r_p^2 + m_d r_d^2$

$I = \dfrac{1}{2}\times 129 \times 1.51^2 + 67.5 \times 1.09^2 + 25.3\times 1.37^2$

I = 274.75 kg-m²

3 0

3 years ago

In a car lift used in a service station, compressed air exerts a force on a small piston that has a circular cross section and a

timofeeve [1]

Answer:

a) F₁ = 1.48 x 10³ N

b) P = 1.88*10⁵ Pa

c) The work is equal in both pistons

Explanation:

Pascal´s Principle can be applied in the hydraulic press:

If we apply a small force (F₁) on a small area piston (A₁), then, a pressure (P) is generated that is transmitted equally to all the particles of the liquid until it reaches a larger area piston and therefore a force (F₂) can be exerted that is proportional to the area(A₂) of the piston.

Pressure is defined as the force per unit area:

$P=\frac{F}{A}$ Formula (1)

P₁=P₂

$\frac{F_{1} }{A_{1} } =\frac{F_{2} }{A_{2} }$ Formula (2)

Data

r₁= 5 cm = 0.05 m

r₂= 15 cm = 0.15 m

F₂= 13300N

Area of the pistons (A₁,A₂)

A=π*r² : Area of the circle

A₁ = π*(0.05)²=7.85*10⁻³ m²

A₂= π*(0.15)²= 70.69*10⁻³ m²

a) Force that compressed air must exert to lift a car weighing 13300 N

We replace data in the formula (2)

$\frac{F_{1} }{A_{1} } =\frac{F_{2} }{A_{2} }$

$F_{1} = \frac{13300*7.85*10^{-3} }{70.69*10^{-3} }$

F₁ = 1.48 x 10³ N

b) Air pressure produced by F₁

We replace data in the formula (1)

$P=\frac{F}{A}$

F₁ = 1.48 x 10³ N , A₁ = 7.85*10⁻³ m²

$P=\frac{1.48*10^{3} }{7.85*10^{-3} }$

P= 1.88*10⁵ Pa

c)The volume of liquid displaced by the small piston is distributed in a thin layer on the large piston, so that the product of the force by the displacement (the work) is equal in both pistons.

3 0

3 years ago

Who is a meteorologist<br>

Alex Ar [27]

Answer:

A meteorologist is a scientist that studies and examines Earth's atmosphere and its interactions with Earth's oceans, land, and biosphere.

Explanation:

Meteorologists use math and science to understand and predict changes in weather and climate.

8 0

3 years ago