Exam 9: Circular Motion

A car with a mass of 1200 kg goes over a hill at a constant speed.The top of the hill can be approximated as an arc length of a circle with a radius of curvature of 210 m.What minimum speed must the car have as it passes over the top of the hill in order to become airborn?

Suppose the people standing at rest with respect to the Earth on the Earth's equator are weightless.The radius of the earth is 6.37 * 10⁶ m.The length of the day under this condition would be

A CD-ROM starts from rest and undergoes uniform angular acceleration until it reaches 26,000 rpm in 0.25 s.If its radius is 0.061 m,how far does a point on its edge travel during this time?

You are riding as a passenger in a car,and you round a corner,and you are pushed against the car door.Which of the following are most accurate?

A ball attached to the end of a string is swung around in a circular path of radius r.If the radius is kept constant and the speed is doubled

A pendulum is composed of a mass m suspended from the ceiling by a massless string of length L.The mass is pulled back,raised and released.If the tension in the string at the bottom of the swing is 2mg,how high was the the mass raised above the bottom of the swing?

The moon Demos is 23,500 km from Mars and orbits once every 30 hours 26 minutes.Assuming that it orbits in a circular path,what is its average speed?

A ball attached to a string moves in a horizontal circle of radius 1 m.It makes one revolution in 4 seconds.The magnitude of its acceleration is

A runner is running on a circular track,which is 200 m in circumference.Find the magnitude of his acceleration when he is running at a constant speed of 10.8 m/s.

A centrifuge in a medical laboratory is to be operated at an angular speed of 3,600 rpm (revolutions per minute).When switched on,it rotates 72.0 times before reaching the prescribed angular speed.Find the constant angular acceleration of the centrifuge while it speeds up.

The angular speed of the minute hand of a clock is _______.

A sports utility vehicle has tires which are 110 cm in diameter.If the wheel is rotated through 30 revolutions,how far forward does a point on the tire travel?

On a curved roadway of radius 100 m,the suggested speed limit is 35 mph (approximately 16 m/s).What must the coefficient of friction be between a car's tires and the road for the car to safely negotiate the curve at the posted speed?

A point on Earth's surface in the northern hemisphere is moving eastward at 1300 km/h.What is the latitude of this point? (The radius of the earth is 6370 km)

Two hikers begin at the same initial location and walk around a circular lake in opposite directions.One walks twice as fast as the other.The circumference of the lake is L.How far does the faster hiker walk before the two hikers meet at the same final location?

Two masses are attached to a 1-meter rope as shown such that half of the rope hangs vertically below the frictionless table.m₁ (= 2 kg)is set into circular motion with speed 3.0 m/s.What is the value of m₂ if m₂ is to remain stationary?

Calgary,Canada is at a latitude of 51.0 degrees north.How fast is Calgary moving eastward as the Earth rotates? (The radius of the earth is 6370 km)

A toy train moves with uniform speed on a circular track.Which of the following statements is true?

A child's top is spinning at a rate of 7.00 rev/s.It takes 30.0 seconds for the top to slow to a rate of 2.00 rev/s.Assuming a constant angular acceleration,what is the magnitude of the angular acceleration of the top?

A small object with a mass of m = 658 g is whirled at the end of a rope in a vertical circle with a radius of r = 137 cm.When it is at the location shown,(mid-height),and its speed is v = 5.54 m/s,calculate the direction of the total force acting on the mass.(as measured from a line drawn from m to the center of the circular path)