Circular Motion 222

In a uniform circular motion map, what is always true? Check all that apply. The dots are different distances apart. Acceleration vectors point in the direction of motion. Velocity vectors are always perpendicular to the circle. Acceleration vectors point toward the center of the circle. Velocity vectors are the same length.

Acceleration vectors point toward the center of the circle. Velocity vectors are the same length.

An object is represented by the dot on the motion map. Which object is most likely represented by the motion map? a satellite in orbit around a moon a child on a swing that just stopped a ball twirled on a string that just broke a car driving around a curve

a ball twirled on a string that just broke

Which motion maps show an object in uniform circular motion? Check all that apply. V W X Y Z

V W Y

A wrecking ball has a mass of 650 kg. It swings from a cable that is 21 m long. The centripetal force on the ball is 56 N. What is the tangential speed of the wrecking ball? 1.3 m/s 1.8 m/s 46 m/s 870 m/s

1.3 m/s

Johanna makes the table below to organize her notes about centripetal forces. Which type of force should she place in the cell marked X? tension gravity friction normal

gravity

As a truck rounds a curve, a box in the bed of the truck slides to the side farthest from the center of the curve. This movement of the box is a result of .

inertia

Julius competes in the hammer throw event. The hammer has a mass of 7.26 kg and is 1.215 m long. What is the centripetal force on the hammer when it has a tangential speed of 31.95 m/s? The answer is rounded off to the nearest whole number. 190 N 840 N 1,400 N 6,100 N

6,100 N

Lucia wants to change the motion map shown so that it shows uniform circular motion. What change should Lucia make? She should change the length of each vector that is tangent to the circle so that it is the same as the vector pointing toward the center at that point. She should change the direction of the vectors that are toward the center of the circle so that each points tangent to the circle opposite the existing tangent vectors. She should change the direction of the vectors that are toward the center of the circle so that each points away from the center of the circle. She should change the lengths of the vectors that point toward the center so that each is the same length

She should change the lengths of the vectors that point toward the center so that each is the same length.

A remote-controlled plane has a mass of 0.386 kg and flies in a circle with a radius of 75 m. The centripetal force on the plane is 4.0 N. What is the tangential speed of the plane? 11 m/s 28 m/s 45 m/s 784 m/s

28 m/s

A ball that has a mass of 0.25 kg spins in a circle at the end of a 1.6 m rope. The ball moves at a tangential speed of 12.2 m/s. What is the centripetal force acting on the ball? 1.9 N 23 N 59 N 93 N

23 N

How do inertia and centripetal force combine to keep an object moving in circular motion? Centripetal force acts toward the center of the circle to overcome inertia, which acts away from the center. Inertia acts toward the center of the circle to overcome centripetal force, which acts away from the center. Centripetal force acts toward the center of the circle, and inertia keeps the object moving forward. Inertia acts toward the center of the circle, and centripetal force keeps the object moving forward.

Centripetal force acts toward the center of the circle, and inertia keeps the object moving forward.

How does a centripetal force cause circular motion? It acts at a right angle to the object's motion and causes the object to constantly change direction. It acts at a right angle to the object's motion and causes the object to constantly change speed. It acts in the direction of the object's motion and causes the object to constantly change direction. It acts in the direction of the object's motion and causes the object to constantly change speed.

It acts at a right angle to the object's motion and causes the object to constantly change direction.

What must be true of a force that causes an object to move in a circular motion? It acts parallel to the velocity and is directed toward the center of the circle. It acts parallel to the velocity and is directed away from the center of the circle. It acts perpendicular to the velocity and is directed toward the center of the circle. It acts perpendicular to the velocity and is directed away from the center of the circle.

It acts perpendicular to the velocity and is directed toward the center of the circle.

An object is in circular motion. How will the object behave if the centripetal force is removed? It would move in a line away from the circle's center. It would move in a line toward the circle's center. It would move in a curved, circular path. It would move in a line tangent to the circular path.

It would move in a line tangent to the circular path.

Without inertia, how would an object that is experiencing a centripetal force behave? It would move in a line away from the circle's center. It would move in a line toward the circle's center. It would move in a curved, circular path. It would move in a line tangent to the circular path.

It would move in a line toward the circle's center.

Scientists are making plans to put a probe in orbit around Earth. They want the probe to enter the orbit shown below. Which arrow shows the direction that the probe should be moving in order for it to enter the orbit? W X Y Z

X

Suchita makes a table to identify the variables used in the equations for centripetal force. What quantities belong in cells X and Y? X: tangential speed Y: radius X: radius Y: tangential speed X: centripetal force Y: mass X: mass Y: centripetal force

X: radius Y: tangential speed

What is the direction of the centripetal force when applied to an object? the direction opposite to the object's velocity the same direction as the object's velocity perpendicular to an object's motion parallel with an object's motion

perpendicular to an object's motion

A child on a spinning playground ride is 0.36 m from the center of the ride. The centripetal force on the child is 19 N. What is the mass of the child if the child has a tangential speed of 0.54 m/s? 3.7 kg 13 kg 23 kg 79 kg

23 kg

A centripetal force causes circular motion because it accelerates an object toward the center of a circle, which changes the direction of motion but not the speed. toward the center of a circle, which changes the speed of motion but not the direction. along the edge of a circle, which changes the direction of motion but not the speed. along the edge of a circle, which changes the speed of motion but not the direction.

toward the center of a circle, which changes the direction of motion but not the speed.