Exam 6: Circular Motion and Other Applications of Newtons Laws

A 0.40-kg mass attached to the end of a string swings in a vertical circle having a radius of 1.8 m.At an instant when the string makes an angle of 40 degrees below the horizontal,the speed of the mass is 5.0 m/s.What is the magnitude of the tension in the string at this instant?

A race car traveling at 100 m/s enters an unbanked turn of 400 m radius.The coefficient of (static)friction between the tires and the track is 1.1.The track has both an inner and an outer wall.Which statement is correct?

An airplane flies in a horizontal circle of radius 500 m at a speed of 150 m/s.If the plane were to fly in the same 500 m circle at a speed of 300 m/s,by what factor would its centripetal acceleration change?

An airplane travels 80 m/s as it makes a horizontal circular turn which has a 0.80-km radius.What is the magnitude of the resultant force on the 75-kg pilot of this airplane?

An amusement ride consists of a car moving in a vertical circle on the end of a rigid boom.The radius of the circle is 10 m.The combined weight of the car and riders is 5.0 kN.At the top of the circle the car has a speed of 5.0 m/s which is not changing at that instant.What is the force of the boom on the car at the top of the circle?

A highway curve has a radius of 0.14 km and is unbanked.A car weighing 12 kN goes around the curve at a speed of 24 m/s without slipping.What is the magnitude of the horizontal force of the road on the car?

An airplane flies in a horizontal circle of radius 500 m at a speed of 150 m/s.If the plane were to fly in the same 1000 m circle at a speed of 300 m/s,by what factor would its centripetal acceleration change?

When a car goes around a circular curve on a level road without slipping,

A rock attached to a string swings in a vertical circle.Which free body diagram could correctly describe the force(s)on the rock when it is at the lowest point?

Frank says that if you release the string when swinging a ball in a horizontal circle,the ball flies out in the radial direction defined by the string at the instant you release the ball.John says that it flies out along a tangent line perpendicular to the string,and that it then drops straight down to the ground.Which one,if either,is correct?

A small dense object is suspended from the rear view mirror in a car by a lightweight fiber.As the car is accelerating at 1.90 m/s²,what angle does the string make with the vertical?

A 0.50-kg mass attached to the end of a string swings in a vertical circle (radius = 2.0 m).When the mass is at the lowest point on the circle,the speed of the mass is 12 m/s.What is the magnitude of the force of the string on the mass at this position?

A 30-kg child rides on a circus Ferris wheel that takes her around a vertical circular path with a radius of 20 m every 22 s.What is the magnitude of the resultant force on the child at the highest point on this trajectory?

A skydiver of 75 kg mass has a terminal velocity of 60 m/s.At what speed is the resistive force on the skydiver half that when at terminal speed?

A hornet circles around a pop can at constant speed once per second in a path with a 12-cm diameter.We can conclude that the hornet's wings must push on the air with force components that are

An airplane moves 140 m/s as it travels around a vertical circular loop which has a 1.0-km radius.What is the magnitude of the resultant force on the 70-kg pilot of this plane at the bottom of this loop?

A boy on board a cruise ship drops a 30.0 gm marble into the ocean.If the resistive force proportionality constant is 0.500 kg/s,what is the terminal speed of the marble in m/s?

A 0.30-kg mass attached to the end of a string swings in a vertical circle (R = 1.6 m),as shown.At an instant when θ = 50°,the tension in the string is 8.0 N.What is the magnitude of the resultant force on the mass at this instant?

A 0.50 kg mass attached to the end of a string swings in a vertical circle (radius = 2.0 m).When the mass is at the highest point of the circle the speed of the mass is 8.0 m/s.What is the magnitude of the force of the string on the mass at this position?

The following equation was obtained by solving a physics problem: The best physical representation of the situation is