Physics Topics 7&8

A small ball is released from rest at position A and rolls down a vertical circular track under the influence of gravity. When the ball reaches position B, which of the indicated directions most nearly corresponds to the direction of the normal force on the ball? (slide 72)

1

A planet has the orbit shown below. Use the 8 labeled points to answer the question. At which point(s) is the y-component of velocity largest? 1.1 only 2.2 and 8 only 3.3 and 7 only 4.4 and 6 only 5.5 only 6.1 and 5 only 7.2, 4, 6, and 8 8.The total energy is the same everywhere. 9.None of the above 10.Impossible to determine

1. 1 only

In a particular trail run, a driver traveled at a constant speed of 50 m/s for one complete lap. In this case, the ratio of the centripetal acceleration at A to that at B is 1. 1/2 2.1/4 3. 2 4. 4 5. the tangential acceleration is zero at both points

1. 1/2

Which of the following trips would consume more fuel for a given spacecraft? 1.a trip from the Earth to the Moon 2.a trip from the Moon to the Earth 3.They both require the same amount of fuel. 4.It is impossible to determine.

1. a trip from the Earth to the moon

If global warming continues, it's likely that some ice from the polar ice caps of the Earth will melt and the water will be distributed closer to the equator. If this occurs, would the length of the day (one rotation) 1.increase. 2.decrease. 3.remain the same.

1. increase

Two identical objects are released from rest from heights R and 2R above the surface of the Earth. After traveling a distance R/2, which object has the larger speed? 1. Object a 2. object b 3. neither, they have the same speed

1. object a

A spool has string wrapped around its center axle and is sitting on a horizontal surface. If the string is pulled at an angle to the horizontal when drawn from the bottom of the axle, the spool will... 1.... roll to the right. 2.... not roll, only slide to the right. 3.... spin and slip, without moving left or right. 4.... roll to the left. 5.None of the above 6.The motion cannot be determined.

1. roll to the right

A spool has string wrapped around its center axle and is sitting on a horizontal surface. If the string is pulled in the horizontal direction when tangent to the bottom of the axle, the spool will... 1.... roll to the right. 2.... not roll, only slide to the right. 3.... spin and slip, without moving left or right. 4.... roll to the left. 5.None of the above 6.The motion cannot be determined.

1. roll to the right

A spool has string wrapped around its center axle and is sitting on a horizontal surface. If the string is pulled in the horizontal direction when tangent to the top of the axle, the spool will... 1.... roll to the right. 2.... not roll, only slide to the right. 3.... spin and slip, without moving left or right. 4.... roll to the left. 5.None of the above 6.The motion cannot be determined.

1. roll to the right

Two spheres, one hollow and one solid, are rotating with the same angular speed around an axis through their centers. Both spheres have the same mass and radius. Which sphere, if either, has the higher rotational kinetic energy? 1.the hollow sphere 2.the solid sphere 3.They have the same kinetic energy.

1. the hollow sphere

Andrea and Chuck are riding on the same merry-go-round, in the same positions. When the merry-go-round is rotating at a constant angular speed, Andrea's angular speed is 1.twice Chuck's. 2.the same as Chuck's. 3.half of Chuck's. 4.impossible to determine.

1. twice Chuck's

Andrea and Chuck are riding on a merry-go-round. Andrea rides on a horse at the outer rim of the circular platform, twice as far from the center of the circular platform as Chuck, who rides on an inner horse. When the merry-go-round is rotating at a constant angular speed, Andrea's linear speed is 1.twice Chuck's. 2.the same as Chuck's. 3.half of Chuck's. 4.impossible to determine.

2. the same as Chuck's

A constant net torque is applied to an object. Which one of the following will not be constant? 1.angular acceleration 2.angular velocity 3.moment of inertia 4.center of gravity

2. angular velocity

A ball is rolled up an incline so that it goes part-way up and then rolls back down. Which of the graphs below could represent its tangential component of acceleration versus time, from the instant it is released until it returns to its starting point? 1. graph 1 2. graph 2 3. graph 3 4. graph 4 5. graphs 1 and 2 6. graphs 3 and 4 7. none 8. its not clear what is meant by "tangential" in this situation

2. graph 2

A skater rotates quickly on the ice. He pushes his arms out. What happens to his angular speed? 1.It increases. 2.It decreases. 3.It stays the same. 4.It is impossible to determine.

2. it decreases

Two blocks hang from strings wound around different parts of a double pulley as shown. Assuming the system is not in equilibrium, what happens to the system's potential energy when it is released from rest? 1.It remains the same. 2.It decreases. 3.It increases. 4.Impossible to determine without knowing the radii of the two pulleys. 5.Impossible to determine without knowing the ratio of the radii of the two pulleys. 6.Impossible to determine for some other reason.

2. it decreases

Someone hits a tether ball to make it spin around a pole. The cord that attaches the tether ball to the central pole then winds around the pole. What happens to the angular speed of the tether ball during this process? 1.It decreases. 2.It increases. 3.It remains constant. 4.It cannot be determined.

2. it increases

Two identical objects are released from rest from heights R and 2R above the surface of the Earth. After traveling a distance R/2, which object has the larger energy? 1. object a 2. object b 3. neither, they have the same speed

2. object b

Select the best phrase to complete the following statement: "The gravitational force of the Earth 1.affects all objects equally." 2.on an object is a function of an object's mass." 3.has no effect on the rate at which objects accelerate as they fall." 4.is exactly the same size for a given object everywhere on the Earth."

2. on an object is a function of an objects mass

A child is standing at the rim of a rotating disk holding a rock. The disk rotates freely without friction. If the rock is dropped at the instant shown, which of the indicated paths most nearly represents the path of the rock as seen from above the disk? 1.path (1) 2.path (2) 3.path (3) 4.path (4) 5.path (5) 6.cannot be determined

2. path (2)

A child is standing at the rim of a freely rotating disk holding a rock. The disk rotates without friction. The rock is dropped at the instant shown. As a result of dropping the rock, what happens to the angular velocity of the child and disk? 1. increase 2. stays the same 3. decrease 4, cannot be determined

2. stays the same

Two blocks hang from strings would around different parts of a 2 k g double pulley as shown. The pivot exerts a normal force F N supporting the double pulley. Assuming the system is not in equilibrium, which statement about F N is true after the system is released from rest? (Use g = 10 N/k g.) 1.​F N = 20 N 2.20 N < F N < 27 N 3.​F N = 27 N 4.​F N > 27N 5.It is impossible to predict what the normal force on the double pulley will be.

2.20 N < F N < 27 N

Estimate the acceleration of the Earth relative to the Sun in m/s^2 1.less than 0.003 2.between 0.003 and 0.03 3.between 0.03 and 0.3 4.between 0.3 and 3 5.between 3 and 30 6.between 30 and 300 7.between 300 and 3,000 8.between 3,000 and 30,000 9.more than 30,000 10.Impossible to determine

2.between 0.003 and 0.03

A disk, with radius 0.25 m and mass 4 k g, lies flat on a smooth horizontal tabletop. A string wound about the disk is pulled with a force of 8 N. What is the angular acceleration of the disk? 1.0 2. 0.5 m/s^2 3. 1 m/s^2 4. 2 m/s^2 5. 4 m/s^2 6. None of the above 7. Cannot be determined

3. 1 m/s^2

A rigid body is rotating counterclockwise about a fixed axis. Each of the following pairs of quantities represent an intial angular position and a final angular position of the rigid body. Which of the sets can only occur if the rigid body rotates through more than 180 degrees? 1. 3 rad, 6 rad 2. -1 rad, 1 rad 3. 1 rad, 5 rad

3. 1 rad, 5 rad

A planet has the orbit shown below. Use the 8 labeled points to answer the question. At which point(s) is the x-component of velocity largest? 1.1 only 2.2 and 8 only 3.3 and 7 only 4.4 and 6 only 5.5 only 6.1 and 5 only 7.2, 4, 6, and 8 8.The total energy is the same everywhere. 9.None of the above 10.Impossible to determine

3. 3 and 7 only

A mass of 5 kg is released from rest on a smooth incline making an angle of 37° to the horizontal. The tangential component of acceleration is closest to: 1. 10 m/s^2 2. 8 m/s^2 3. 6 m/s^2 4. 4 m/s^2 5. 2 m/s^2 6. 0 m/s^2 7. exactly halfway between 2 of the above answers 8. the negative of one of the answers above 9.It is impossible to determine the tangential component of the block's acceleration 10.I do not know what is meant by "tangential" in this situation

3. 6 m/s^2

A horizontal disk with moment of inertia I1 rotates with angular speed ω1 about a vertical frictionless axle. A second horizontal disk, with moment of inertia I2 drops onto the first, initially not rotating but sharing the same axis as the first disk. Because their surfaces are rough, the two disks eventually reach the same angular speed w. the ratio w/w1 is equal to 1. I1/I2 2. I2/ I1 3. I1/(I1+I2) 4. I2/(I1+I2)

3. I1/(I1+I2)

A uniform disk with mass M and radius R sits at rest on an incline 30° to the horizontal. A string is wound around the disk and attached to the top of the incline as shown. The string is parallel to incline. What is the tension in the string? 1. Mg/2, down the incline 2. Mg/2, up the incline 3. Mg/4, up the incline 4. Mg/0.86, down the incline 5. none of the above 6. cannot be determined

3. Mg/4, up the incline

An iceberg weighing 1,000 tons is floating in the North Atlantic. Consider the gravitational forces on the iceberg due to the Earth, the Moon, and the Sun. Put these gravitational forces in order of increasing magnitude. You do not need to do any calculations. Use reasoning, or simply guess. 1.Earth < Moon < Sun 2.Earth < Sun < Moon 3.Moon < Sun < Earth 4.Moon < Earth < Sun 5.Sun < Moon < Earth 6.Sun < Earth < Moon

3. Moon < Sun < Earth

A planet has the orbit shown below. Use the 8 labeled points to answer the question. Where is the planet when the total energy of the system is largest? 1.1 only 2.2 and 8 only 3.3 and 7 only 4.4 and 6 only 5.5 only 6.1 and 5 only 7.2, 4, 6, and 8 8.The total energy is the same everywhere. 9.None of the above 10.Impossible to determine

8. the total energy is the same everywhere

Estimate the speed of the Earth relative to the Sun in m/s 1.less than 0.003 2.between 0.003 and 0.03 3.between 0.03 and 0.3 4.between 0.3 and 3 5.between 3 and 30 6.between 30 and 300 7.between 300 and 3,000 8.between 3,000 and 30,000 9.more than 30,000 10.Impossible to determine

8.between 3,000 and 30,000

A child is standing at the rim of a rotating disk, and throws a rock radially outward at the instant shown. The disk rotates freely without friction. Which of the following statements is correct about the disk-child-rock system as the rock is thrown? 1.Angular momentum is conserved, mechanical energy increases. 2.Angular momentum is conserved, mechanical energy decreases. 3.Angular momentum increases, mechanical energy is conserved. 4.Angular momentum decreases, mechanical energy is conserved. 5.Both angular momentum and mechanical energy are conserved. 6.Both angular momentum and mechanical energy increase. 7.Angular momentum decreases, mechanical energy increases. 8.Angular momentum increases, mechanical energy decreases. 9.Both angular momentum and mechanical energy decrease. 10.The conserved quantities cannot be determined.

1.Angular momentum is conserved, mechanical energy increases.

A child is standing at the rim of a rotating disk holding a rock, and throws a rock in direction (2) at the instant shown. The disk rotates freely without friction. What happens to the angular speed of the disk? 1. increases 2. remains the same 3. decreases 4. impossible to determine

1.increases

Estimate the acceleration of the Moon relative to the center of the Earth in m/s^2 1.less than 0.003 2.between 0.003 and 0.03 3.between 0.03 and 0.3 4.between 0.3 and 3 5.between 3 and 30 6.between 30 and 300 7.between 300 and 3,000 8.between 3,000 and 30,000 9.more than 30,000 10.Impossible to determine

1.less than 0.003

A small ball is released from rest at position A and rolls down a vertical circular track under the influence of gravity as depicted below. When the ball reaches position B, which of the indicated directions most nearly corresponds to the direction of the net force on the ball?(slide 74)

2

A small ball is released from rest at position A and rolls down a vertical circular track under the influence of gravity. When the ball reaches position B, which of the indicated directions most nearly corresponds to the direction of the ball's acceleration? (slide 73)

2

A 100-k g crate is attached to a rope wrapped around the inner disk as shown. A person pulls on another rope wrapped around the outer disk with force F to lift the crate. What force F is needed to lift the crate 2 m? 1.about 400 J 2.slightly less than 2,000 J 3.Exactly 2,000 J 4.slightly more than 2,000 J 5.much more than 2,000 J 6.Impossible to determine without knowing F 7.Impossible to determine without knowing the radii 8.Impossible to determine without knowing the mass of the pulley 9.Impossible to determine for two or more of the reasons given in 6, 7, and 8 above 10.Impossible to determine for some other reason(s)

2, 3, 4, and 5

A rigid body is rotating counterclockwise about a fixed axis. Each of the following pairs of quantities represents an initial angular position and a final angular position of the rigid body. If the object starts from rest at the initial angular position, moves counterclockwise with constant angular acceleration, and arrives at the final angular position with the same angular speed in all three cases, for which choice is the angular acceleration the highest? 1.3 rad, 6 rad 2.−1 rad, 1 rad 3.1 rad, 5 rad

2. -1 rad, 1 rad

A rigid body rotates counterclockwise about a fixed axis for one second. Each of the following pairs of quantities represent an initial angular position and a final angular position of the rigid body. Which choice represents the lowest angular speed? 1. 3 rad, 6 rad 2. -1 rad, 1 rad 3. 1 rad, 5 rad

2. -1 rad, 1 rad

In a particular trail run, a driver traveled at a constant speed of 50 m/s for one complete lap. In this case, the angular speed is greatest at 1. A 2. B 3. It is equal at both A and B

2. B

The two rigid objects shown in the figures have the same mass, radius, and angular speed. If the same braking torque is applied to each, which takes longer to stop? 1. A 2. B 3. more information is needed

2. B

A uniform rod of length 4L, mass M, is suspended by two thin strings, lengths L and 2L as shown. What is the tension in the string at the left end of the rod? 1. Mg 2. Mg/2 3. Mg/3 4. Mg/4 5. none of the above

2. Mg/2

The Earth remains in orbit about the Sun, rather than falling in to the Sun, because 1.it is outside of the gravitational influence of the Sun. 2.the net force on the Earth is zero. 3.although the Earth is constantly being pulled toward the Sun, it is always moving with a velocity component perpendicular to the direction that it is being pulled. 4.none of these apply.

3. although the earth is constantly being pulled toward, the sun it is always moving with a velocity component perpendicular to the direction that it is being pulled

An object moves in a circular path with constant speed v. Which of the following statements is true concerning the object? 1.Its velocity is constant, but its acceleration is changing. 2.Its acceleration is constant, but its velocity is changing. 3.Both its velocity and acceleration are changing. 4.Its velocity and acceleration remain constant.

3. both its velocity and acceleration are changing

Two masses m1 and m2, having m1 > m2, are launched with the same speed in the direction a. Which mass reaches the greatest height? 1. m1 2. m2 3. both reach the same height

3. both reach the same height

Two masses m1 and m2, having m1 > m2, are launched with the same speed in the direction b. Which mass reaches the greatest height? 1. m1 2. m2 3. both reach the same height

3. both reach the same height

A space station orbits the Earth with a constant speed. What can be said about the space station? 1. it is zero because the space station moves with constant speed 2. it is greater than 9.8 m/s^2 because the space station is moving so quickly 3. it is less than 9.8 m/s^2 because the space station is so high above the Earths surface 4. it is equal to 9.8 m/s^2

3. it is less than 9.8 m/s^2 because the space station is so high above the Earths surface

Which of the following screwdrivers would likely be the most effective to loosen a stubborn screw? Assume the size of the driver head is the same in each case. 1.one with a handle that is 8 c m long and 2 c m wide 2.one with a handle that is 12 c m long and 2 c m wide 3.one with a handle that is 8 c m long and 4 c m wide 4.They would all loosen the screw just as effectively.

3. one with a handle that is 8cm long and 4cm wide

A ball rolls without slipping down incline A, starting from rest. At the same time, a box starts from rest and slides down incline B, which is identical to incline A except it is frictionless. Which has a larger translational speed at the bottom of the ramp? 1.They have the same translational speed at the bottom of the ramp. 2.the ball 3.the box 4.It is impossible to determine.

3. the box

Which of the following forms of energy is the greatest for a system of a comet in orbit about the Sun during perihelion (the comet's closest approach to the Sun). 1.the total mechanical energy 2.the potential energy 3.the kinetic energy 4.none of these

3. the kinetic energy

A uniform rod of length L, mass M, is suspended by two thin strings. Which of the following statements is true regarding the tensions in the strings? 1.T2 = T1 2.T2 = 2.5 T1 3.T2 = 0.6 T1 4.T2 = 0.8 T1 5.None of the above 6.Not enough information to determine

3.T2 = 0.6 T1

An object is at rest on the equator. Estimate its acceleration relative to the center of the Earth in m/s^2 1.less than 0.001 2.between 0.001 and 0.01 3.between 0.01 and 0.1 4.between 0.1 and 1 5.between 1 and 10 6.between 10 and 100 7.between 100 and 1,000 8.between 1,000 and 10,000 9.more than 10,000 10.Impossible to determine

3.between 0.01 and 0.1

A disk, with radius 0.25 m and mass 4 k g, lies flat on a smooth horizontal tabletop. A string wound about the disk is pulled with a force of 8 N. What is the acceleration of the disk? 1.0 2. 0.5 m/s^2 3. 1 m/s^2 4. 2 m/s^2 5. 4 m/s^2 6. none of the above 7. cannot be determined

4. 2 m/s^2

Suppose an asteroid has a semimajor axis of 4 AU. How long does it take the asteroid to go around the Sun? 1. 2 years 2. 4 years 3. 6 years 4. 8 years

4. 8 years

A uniform disk with mass M and radius R sits at rest on an incline 30° to the horizontal. A string is wound around the disk and attached to the top of the incline as shown. The string is parallel to incline. What is the tension in the string? 1. Mg 2. Mg/2 3. 2Mg/5 4. Mg/4 5. none of the above 6. cannot be determined

4. Mg/4

A 100 k g crate is attached to a rope wrapped around the inner disk as shown. A person pulls on another rope wrapped around the outer disk with force F to lift the crate. What force F is needed to lift the crate 2 m? 1.about 20 N 2.about 50 N 3.about 100 N 4.about 200 N 5.about 500 N 6.about 1,000 N 7.about 2,000 N 8.about 5,000 N 9.Impossible to determine without knowing the radii 10.Impossible to determine for some other reason(s)

4. about 200 N

A rigid object is rotating with an angular speed ω > 0. The angular velocity vector w and the angular acceleration vector a are anti-parallel. The angular speed of the rigid object is 1.clockwise and increasing. 2.clockwise and decreasing. 3.counterclockwise and increasing. 4.counterclockwise and decreasing.

4. counterclockwise and decreasing

Complete the following sentence: "The moment of inertia of an object 1.depends on the rotational speed of the object." 2.will be greater for a larger-massed object than for a smaller-massed object." 3.is not a function of the object's mass." 4.is a function of the axis about which the object is spun."

4. is a function of the axis about which the object is spun

Using a screwdriver, you try to remove a screw from a piece of furniture, but can't get it to turn. To increase the chances of success, you should use a screwdriver that 1.is longer. 2.is shorter. 3.has a narrower handle. 4.has a wider handle.

4. it has a wider handle

A child is standing at the rim of a disk holding a rock. The disk rotates freely without friction. At the instant shown, the child throws the rock radially outward. Which of the indicated paths most nearly represents the trajectory of the rock as seen from above? 1.path (1) 2.path (2) 3.path (3) 4.path (4) 5.path (5) 6.none of the above 7.cannot be determined

4. path (4)

Estimate the speed of the Moon relative to the center of the Earth in m/s 1.less than 0.003 2.between 0.003 and 0.03 3.between 0.03 and 0.3 4.between 0.3 and 3 5.between 3 and 30 6.between 30 and 300 7.between 300 and 3,000 8.between 3,000 and 30,000 9.more than 30,000 10.Impossible to determine

7.between 300 and 3,000

A ball is falling toward the ground. Which of the following statements are false? a) The force that the ball exerts on the Earth is equal in magnitude to the force that the Earth exerts on the ball. b) The ball undergoes the same acceleration as Earth. c) The magnitude of the force the Earth exerts on the ball is greater than the magnitude of the force the ball exerts on the Earth. 1. statements a and b are false 2. statements a, b, and c are all false 3. statements a and c are false 4. statements b and c are false

4. statements b and c are false

A uniform rod is hinged to a wall and held at a 30° angle by a thin string that is attached to the ceiling and makes a 90° angle to rod. Which statement(s) must be true? (At least one of them is true and at least one is false.) 1.The hinge force is purely vertical. 2.The hinge force is purely horizontal. 3.The string tension is equal to the hinge force. 4.The string tension is smaller than the rod's weight. 5.1 and 3 are true. 6.2 and 3 are true. 7.1 and 4 are true. 8.2 and 4 are true 9.3 and 4 are true. 10.Three of the statements are true.

4. the string tension is smaller than the rod's weight

The center of gravity is a useful point at which to balance an object. For instance, a ruler can be balanced by placing its center on your finger. Is it possible for the center of gravity of an object to be located at a point where no material exists to balance the object? 1.no, never 2.only for very unsymmetrical objects 3.It is possible in theory, but no objects have been found for which this occurs. 4.Yes, it is possible.

4. yes it is possible

An ice skater begins a spin in the middle of a large rink, but then starts to spin faster by pulling her arms in. Which of the following statements is true? 1.Both kinetic energy and angular momentum are conserved. 2.Kinetic energy is conserved; angular momentum increases. 3.Kinetic energy is conserved; angular momentum decreases. 4.Kinetic energy increases; angular momentum is conserved. 5.Kinetic energy decreases; angular momentum is conserved. 6.Both kinetic energy and angular momentum increase. 7.Kinetic energy increases; angular momentum decreases. 8.Kinetic energy decreases; angular momentum increases. 9.Both kinetic energy and angular momentum decrease. 10.Impossible to determine.

4.Kinetic energy increases; angular momentum is conserved.

The rotational inertia of the dumbbell (see figure) about axis A is twice the rotational inertia about axis B. The unknown mass is: 1. 4/7 kg 2.2 kg 3.4 kg 4.5 kg 5.7 kg 6.8 kg 7.10 kg 8.None of the above 9.Cannot be determined 10.The rotational inertia cannot be different about different axes.

5. 7 kg

A planet has two identical moons with identical mass. Moon 1 is in a circular orbit of radius r. Moon 2 is in a circular orbit of radius 2r. The magnitude of the gravitational force exerted by the planet on Moon 2 is 1.four times as large as the gravitational force exerted by the planet on Moon 1. 2.twice as large as the gravitational force exerted by the planet on Moon 1. 3.the same as the gravitational force exerted by the planet on Moon 1. 4.half as large as the gravitational force exerted by the planet on Moon 1. 5.one-fourth as large as the gravitational force exerted by the planet on Moon 1.

5. one-fourth as large as the gravitational force exerted by the planet on moon 1

A race track is constructed such that two arcs of radius 80 m at A and 40 m at B are joined by two stretches of straight tracks as in the figure. In a particular trial run, a driver traveled at a constant speed of 50 m/s for one complete lap. In this case, the ratio of the tangential acceleration at A to that at B is 1. 1/2 2. 1/4 3. 2 4. 4 5. the tangential acceleration is zero at both points

5. the tangential acceleration zero at both points

A child is standing at the rim of a freely rotating disk holding a rock. The disk rotates without friction. The rock is dropped at the instant shown. Which of the following statements is true about the process of dropping the rock? 1.Angular momentum is conserved, mechanical energy increases. 2.Angular momentum is conserved, mechanical energy decreases. 3.Angular momentum increases, mechanical energy is conserved. 4.Angular momentum decreases, mechanical energy is conserved. 5.Both angular momentum and mechanical energy are conserved. 6.Both angular momentum and mechanical energy increase. 7.Angular momentum decreases, mechanical energy increases. 8.Angular momentum increases, mechanical energy decreases. 9.Both angular momentum and mechanical energy decrease. 10.The conserved quantities cannot be determined.

5.Both angular momentum and mechanical energy are conserved.

A mass of 5 kg is released from rest on a smooth incline making an angle of 37° to the horizontal. The radial component of acceleration is closest to: 1. 10 m/s^2 2. 8 m/s^2 3. 6 m/s^2 4. 4 m/s^2 5. 2 m/s^2 6. 0 m/s^2 7. exactly halfway between 2 of the above answers 8. the negative of one of the answers above 9.It is impossible to determine the tangential component of the block's acceleration 10.I do not know what is meant by "tangential" in this situation

6. 0 m/s^2

A planet has the orbit shown below. Use the 8 labeled points to answer the question. At which point(s) is the speed of the planet smallest? 1.1 only 2.2 and 8 only 3.3 and 7 only 4.4 and 6 only 5.5 only 6.1 and 5 only 7.2, 4, 6, and 8 8.The total energy is the same everywhere. 9.None of the above 10.Impossible to determine

6. 1 and 5 only

A mass m is launched from the surface of the Earth with speed v. The diagram shows three possible launch directions; order them according to the maximum height the projectile will reach, from greatest height to least height. 1..a = b = c 2.a < b = c 3.a < b < c 4.a < c < b 5.a > b = c 6.a > b > c 7.a > c > b 8.b > a > c 9.b > a = c 10.Not enough information

6.a > b > c

Which situation has the least magnitude of angular momentum about the origin? A. A 2-kg mass travels along the line y=3m with speed 1.5m/s B. A 1-kg mass travels in a circle of r=4.5m about the origin with speed 2 m/s C. A disk with I=3 kg*m^2 rotates about its center (on origin) with w = 3 rad/s 1.A 2.B 3.C 4.Both A and B 5.Both A and C 6.Both B and C 7. all have the same magnitude angular momentum

7. all have the same magnitude angular momentum

An object is at rest on the equator. Estimate its speed relative to the center of the Earth in m/s 1.less than 0.001 2.between 0.001 and 0.01 3.between 0.01 and 0.1 4.between 0.1 and 1 5.between 1 and 10 6.between 10 and 100 7.between 100 and 1,000 8.between 1,000 and 10,000 9.more than 10,000 10.Impossible to determine

7.between 100 and 1,000