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2 years ago

Friction is a force in which two objects __________.

Physics

2 answers:

balu736 [363]2 years ago

7 0

The answer should be C) Slide against each other.

Kazeer [188]2 years ago

4 0

Answer:

Explanation:

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A ball rolls down a ramp. A small amount of friction heats up the ball. What energy transformations are taking place?

Natasha2012 [34]

Answer:kinetic energy converted to heat energy

Explanation:

As the ball rolls down kinetic energy is converted to heat energy

6 0

3 years ago

Read 2 more answers

What do scientists theorize about the origins of the Moon? Choose the most accepted explanation.

Darina [25.2K]

Answer:

What is most widely accepted today is a the giant-impact theory. It proposes that the Moon formed during a collision between the Earth and another small planet, about the size of Mars. The debris from this impact collected in an orbit around Earth to form the Moon.

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2 years ago

Professional Application: A 30,000-kg freight car is coasting at 0.850 m/s with negligible friction under a hopper that dumps 11

Nataliya [291]

Answer:

0.182 m/s

Explanation:

m1 = 30,000 kg, m2 = 110,000 kg, u1 = 0.85 m/s

let the velocity of loaded freight car is v

Use the conservation of momentum

m1 x u1 + m2 x 0 = (m1 + m2) x v

30,000 x 0.85 = (30,000 + 110,000) x v

v = 0.182 m/s

5 0

3 years ago

NEED NOW ALMOST DUE

Arte-miy333 [17]

Answer:

Asteroids are objects made of clay and silicate that orbit the sun but are too small to be considered planets.

Most asteroids revolve around the sun in an orbit between those of Mars and Jupiter.

They form a wide band called the Asteroid belt.

Other asteroids have orbits that cross Earth’s orbit. These asteroids are called Earth-crossers.

Asteroids probably consist of matter that never agglomerated into a planet when the solar system was forming.

The comet’s core is composed of ice and dust.

Comets heat up and begin to change from a solid to a gas as they approach the sun.

The matter surrounding a comet’s core is vaporized and forms a very bright halo of ice or dust not sure, and an enormous cloud of dust or gasses not sure envelopes the head of the comet.

7 0

2 years ago

Suppose you are standing on top of a hemisphere of radius r and you kick a soccer ball horizontally such that it has velocity v.

Ksivusya [100]

$|v| =\sqrt{ G \cdot M / r}$ , where

$M$ the mass of the planet, and
$G$ the universal gravitation constant.

Explanation:

Minimizing the initial velocity of the soccer ball would minimize the amount of mechanical energy it has. It shall maintain a minimal gravitational potential possible at all time. It should therefore stay to the ground as close as possible. An elliptical trajectory would thus be unfavorable; the ball shall maintain a uniform circular motion as it orbits the planet.

Equation 1 (see below) relates net force the object experiences, $\Sigma F$ to its orbit velocity $v$ and its mass $m$ required for it to stay in orbit :

$\Sigma F = m \cdot v^{2} / r$ (equation 1)

The soccer ball shall experiences a combination of gravitational pull and air resistance (if any) as it orbits the planet. Assuming negligible air resistance, the net force $\Sigma F$ acting on the soccer ball shall equal to its weight, $W = m \cdot g$ where $g$ the gravitational acceleration constant. Thus

$\Sigma F = W = m \cdot g$ (equation 2)

Substitute equation 2 to the left hand side of equation 1 and solve for $v$ ; note how the mass of the soccer ball, $m$ , cancels out:

$m \cdot g = \Sigma F = m \cdot v^{2} / r \\ v^{2} = g \cdot r \\ |v| = \sqrt{g \cdot r} \; (|v| \ge 0)$ (equation 3)

Equation 4 gives the value of gravitational acceleration, $g$ , a point of negligible mass experiences at a distance $r$ from a planet of mass $M$ (assuming no other stellar object were present)

$g = G \cdot M/ r^{2}$ (equation 4)

where the universal gravitation constant $G = 6.67408 \times 10^{-11} \cdot \text{m}^{3} \cdot \text{kg}^{-1} \cdot \text{s}^{-2}$

Thus

$\begin{array}{lll}|v| &=& \sqrt{g \cdot r}\\ & =&\sqrt{ G \cdot M / r}\end{array}$

3 0

3 years ago