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1. A paper pinwheel is spinning in the wind. Which statement is correct about the forces responsible for the rotation?

The components of gravity and the force of wind that point through the pivot are responsible for the rotation.

Only the perpendicular component of wind is responsible for the rotation, because gravity points downward.

Only the perpendicular component of gravity is responsible for the rotation, because wind points toward the pivot. <- MY ANSWER

The perpendicular components of gravity and the force of wind are responsible for the rotation.

2. Which statement about kinetic and static friction is accurate?

Static friction is greater than kinetic friction, but they both act opposite the applied force.

Static friction is greater than kinetic friction, and they both act in conjunction with the applied force.

Kinetic friction is greater than static friction, but they both act opposite the applied force.

Kinetic friction is greater than static friction, and they both act in conjunction with the applied force.

3. A group of engineers is preparing a satellite to land by moving it 10% closer to Earth in each rotation. Which statement is correct about the rotational inertia of the satellite?

Rotational inertia decreases proportional to the decrease in the radius of rotation.

Rotational inertia increases proportional to the decrease in the radius of rotation. <- MY ANSWER

Rotational inertia first decreases and then increases as the satellite is ready to land.

Rotational inertia does not change because it is conserved.

4. In the experimental setup shown (see image attached), a car has one end of a string attached to it. The other end of the string has a hanger on which metal discs can be added or removed. The car moves along the table, and two photogate probes sense the motion of the car. The probes send information to a computer that displays the experimental results.
Which quantity is being held constant in this experiment?

mass
force
acceleration
velocity <- MY ANSWER

1. A paper pinwheel is spinning in the wind. Which statement is correct about the-example-1
User Hajamie
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2 Answers

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Answer:

1. The perpendicular components of gravity and the force of wind are responsible for the rotation.

2. Static friction is greater than kinetic friction, but they both act opposite the applied force.

3. Rotational inertia decreases proportional to the decrease in the radius of rotation.

4. mass

User Kevin Quinzel
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4 votes

Answer:

1) Only the perpendicular component of wind is responsible for the rotation, because gravity points downward.

2) static friction is greater than kinetic friction and the applied force acts oppositely

3) Inertia decreases with decreasing radius of the orbit.

4) constant is the mass of the car

Step-by-step explanation:

1) In order to know which statement is correct, let's analyze the movement of the mill.

The rotation of the blades due to a force perpendicular to each one, which creates a torque that results in its rotation.

The true force does not affect the movement because it is applied at the center of mass of the mill that coincides with its axis of rotation.

Of the statements, the correct one is:

The perpendicular to the wind is responsible for the movement

2) static friction is the result of microscopic bonds between two surfaces when there is no relative motion between them

kinetic friction is the result of the unions between the two surfaces when there is a relative movement between them.

From these statements it follows that friction is contrary to motion, static friction must be greater than kinetic friction.

Of the statements the correct one is:

static friction is greater than kinetic friction and the applied force acts oppositely

3) The inertia of a particle is

I = m R²

where m is the mass of the satellite and R is the distance from the center of the Earth, decreasing with each orbit

The correct answer is:

Inertia decreases with decreasing radius of the orbit.

4) From the figure it can be seen that the motorist subjected to a constant force, for which we can apply Newton's second law

F = m a

The force equals the applied weight.

The quantity that is held constant is the mass of the car

since the applied force and therefore the acceleration can be changed by changing the applied weight.

User Manish Arora
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