Forces 4 Flashcards
What happens to the speed of an object moving in a circular path if the force perpendicular to the motion increases, with mass and radius kept constant?
The speed increases.
What happens to the radius of an object’s circular motion if the force perpendicular to the motion increases, with mass and speed kept constant?
The radius decreases.
If the mass of an object moving in a circular path increases, what must happen to the force to maintain constant speed and radius?
The force must increase.
Why does an object move in a circular path under a perpendicular force?
The perpendicular force changes the direction of the object’s velocity continuously, causing it to follow a circular path.
What is the direction of the force acting on an object in circular motion?
The force is directed towards the center of the circular path (centripetal force).
A ball is whirled in a horizontal circle on a string. If the tension in the string increases, describe what happens to the radius of the circle, assuming the speed of the ball is constant.
The radius of the circle decreases.
A car takes a turn on a circular track. If the mass of the car doubles and the speed remains the same, how must the centripetal force change to keep the radius constant?
The centripetal force must double.
A toy plane moves in a vertical circular path. At the top of the path, the speed decreases. Explain why.
At the top of the path, gravitational force acts in the same direction as the centripetal force, reducing the need for as much speed to maintain the circular motion.
A stone is tied to a string and whirled in a circle. If the string breaks, describe the motion of the stone.
The stone moves in a straight line tangent to the circular path at the point where the string breaks.
A cyclist is riding around a circular track. What factors determine the maximum speed at which the cyclist can move without skidding off the track?
The maximum speed depends on the coefficient of friction between the tires and the track and the radius of the circular path.
