UCM Chapter Test

Centripetal force is inversely proportional to 

• mass 
• velocity
• radius
• weight 

Centripetal force is directly  proportional to 

• diameter 
• velocity
• radius
• weight 

If an object is moving with constant speed and has a acceleration towards the center of its circular its velocity is 

• In the same direction as the net force           
• Curves along the perimeter of the circle       
• opposite to the objects acceleration 
• tangent to the circle & perpendicular to the force

When an object experiences uniform circular motion, the direction of its net force F and acceleration a is always   

• the same as that of its velocity                             
• opposite that of its velocity   
• away from the center of the circular path.             
• towards the center of the circular path

Can objects moving with constant speed accelerate?  Explain. 

• Yes, if an object is moving it must be accelerating
• No, if the speed is constant then the acceleration must equal to zero. 
• Yes, although the speed is constant, the object may be changing direction 
• Yes, if it is moving a force must be acting on it, so it must be accelerating

A car goes around a curve of radius r at a constant speed v.  Then it goes around a curve of radius 2r at speed 4v.  What is the centripetal force on the car as it goes around the second curve, compared to the first? 

• four times as big             
• two times as big                   
• six times as big                         
• eight times as big 

The number of cycles per unit of time is the 

• frequency
• period
• number of cycles 
• total time

The time it takes to make one complete cycle is called 

• frequency
• period 
• number of cycles 
• total time

A roller coaster makes a vertical loop around its track. When it gets to the top of the loop gravity and normal force are 

•  perpendicular to each other
• both point upwards
• both point downwards
• point in opposite directions

A roller coaster makes a vertical loop around its track. When it gets to the bottom of the loop gravity and normal force are 

•  perpendicular to each other
• both point upwards
• both point downwards
• point in opposite directions