Mr. King's Chapter 10 Physics Test

When the string suddenly breaks, the can will continue to move in a straight line tangent to its circular path. This is because of the concept of inertia, which states that an object in motion will continue moving in a straight line unless acted upon by an external force. In this case, the can was already moving in a circular path due to the string's tension, and when the string breaks, the can will no longer be subject to that force and will fly off in a straight line tangent to its circular path.

The horse near the outside rail of a merry-go-round has a greater linear speed compared to the horse near the inside rail. This is because the outside horse has to cover a longer distance in the same amount of time as the inside horse. The merry-go-round rotates in a circular motion, and the outside horse has to travel a larger circumference compared to the inside horse. Therefore, the outside horse has a greater linear speed.

During the spin cycle of a washing machine, the clothes are pushed against the inner walls of the machine due to the centrifugal force. This force is directed towards the center of rotation, causing the clothes to move inward. Therefore, the correct answer is inward.

The angular speed of an object is determined by its rotational motion and is defined as the rate at which it rotates around a specific axis. In the case of a merry-go-round, all points on the rotating platform have the same angular speed because they complete one revolution in the same amount of time. Therefore, both the horse near the outside rail and the horse near the inside rail have the same angular speed.

The correct answer is that the net force on the car is directed toward the center of the curve. This is because when an object moves in a circular path, it experiences a centripetal force that is directed toward the center of the circle. This force is necessary to keep the object moving in a curved path and is responsible for causing the object to continuously change its direction. Since the car in this scenario is traveling in a circle with constant speed, it is not accelerating, meaning that the net force on the car must be zero. Therefore, the force must be directed toward the center of the curve.

The correct answer is that there is an inward force acting on the can. When the tin can is whirled on the end of a string, it moves in a circle due to the centripetal force acting on it. This force is directed towards the center of the circle and keeps the can moving in a circular path. Without this inward force, the can would move in a straight line instead of a circle. Therefore, the presence of an inward force is necessary for the can to move in a circle.

As the ladybug is resting on the bottom of the tin can, it is in contact with the can. When the can is being whirled horizontally on the end of a string, it experiences centripetal force, which acts towards the center of the circular motion. This force is exerted by the can on the ladybug, causing it to move in a circle along with the can. Therefore, the can exerts the force on the ladybug.

Inside the rotating space structure, the force experienced by a person is directly proportional to the distance from the axis of rotation. Since people on the inside of the outer edge experience 1 g, it means that they are at a distance where the force is equal to their weight. On the other hand, people halfway to the axis will experience 1/2 g, which means they are at a distance where the force is half of their weight. This can be explained by the fact that the centripetal force required to keep an object moving in a circle is proportional to the square of its distance from the axis of rotation.

When a railroad train rounds a banded track, the centripetal force needed comes from the horizontal component of the normal force. The normal force is the force exerted by a surface to support the weight of an object resting on it. In this case, the normal force is exerted by the track on the train. As the train rounds the curved track, the normal force has both a vertical and a horizontal component. The vertical component supports the weight of the train, while the horizontal component provides the centripetal force necessary to keep the train moving in a curved path.

As Biker Bob rides his bike in the opposite direction to the station's rotation, he experiences a centrifugal force that pushes him away from the center of the rotating doughnut-shaped structure. This centrifugal force reduces the normal force acting on him, causing it to decrease. This decrease in the normal force makes it feel like he has less weight while riding his bike inside the rotating space station.

In a rotating reference frame, objects appear to experience a centrifugal force that pushes them away from the center of rotation. This is because the frame itself is accelerating, and objects within it seem to move outward due to their inertia. This apparent force is not actually a true force, but rather a result of the observer's perspective. Therefore, in a rotating reference frame, observers perceive centrifugal forces.

As the rotational speed of a space habitat increases, the weight of people inside increases. This is because the centrifugal force, which is experienced as a pseudo-force pushing outward, becomes stronger with higher rotational speed. This force counteracts the force of gravity, making the effective weight of individuals inside the habitat greater. Therefore, the weight of people inside the habitat increases as the rotational speed increases.

As Biker Bob rides his bike inside the rotating space station, the bike and Bob himself are also rotating with the station. The normal force is the force exerted by a surface to support the weight of an object resting on it. In this case, the rotating station acts as the surface supporting Bob and his bike. As the bike moves in the same direction as the station's rotation, it experiences a centrifugal force that pushes it outward. To counteract this force and keep the bike on the surface, the normal force needs to increase. Therefore, the correct answer is that the normal force increases.

When a motorcyclist rides on the inner vertical surface of a circular track, the centripetal force required to keep them moving in a circular path is provided by the normal force. The normal force is the force exerted by a surface perpendicular to the surface, and in this case, it acts towards the center of the circular track. This force counteracts the gravitational force (weight) acting downwards and provides the necessary inward force to keep the motorcyclist moving in a circular path. Therefore, the correct answer is the normal force.

In a space habitat, the variation in gravitational force (g) between a person's head and feet is less than 0.01 g. This means that the difference in gravitational force experienced by the person's head and feet is very small. To calculate the radius of the habitat, we can use the formula for gravitational force: g = G * (M / r^2), where G is the gravitational constant, M is the mass of the habitat, and r is the radius of the habitat. Since the variation in g is less than 0.01 g, we can assume that the difference in r^2 is also very small. Therefore, the radius of the habitat must be relatively small, and the correct answer is 200 m.

When Nellie Newton swings the rock in a circular path, the string attached to it forms a conical pendulum. In this case, the centripetal force that keeps the rock in its circular path is provided by the horizontal component of the string tension. The vertical component of the string tension only counteracts the weight of the rock, while the tension in the string is a combination of both the vertical and horizontal components. Therefore, the correct answer is the horizontal component of the string tension.

If Earth rotated more slowly about its axis, the centrifugal force caused by the rotation would be weaker. This would result in a decrease in the outward force acting on objects, including our bodies. As a result, our weight would increase because the gravitational force pulling us towards the center of the Earth would be relatively stronger compared to the centrifugal force.

In a rotating cylinder in space, the centrifugal force cancels out the gravitational force along the axis of the habitat. This is because the centrifugal force acts outward from the axis, counteracting the downward pull of gravity. As a result, the net gravitational force along the axis is zero, making the answer "zero" correct.

In a 0.25 g region, the person experiences a quarter of the gravitational force compared to a 1 g region. Since the person can jump 0.5 m high in a 1 g region, in a 0.25 g region they will be able to jump four times higher, which is 2 m.

Earth rotates about the North/South pole, which is an internal axis. This rotation causes day and night on Earth. Earth also revolves around the sun, which is an external axis. This revolution takes approximately 365.25 days to complete, resulting in the changing of seasons.