How Does Hitting a Cue Ball Above the Equator Affect Its Motion?

In summary, a cue ball with a mass of 250 g and a diameter of 6 cm is hit 4.5 cm above the horizontal surface it is on, with an average force of 6000 N during a contact time of 20 usec. The cue ball's speed after being hit is unknown, but the equations F=ma and x=x0+v0xt+1/2at^2 may be used to calculate it by taking into account the torque on the ball caused by being hit off center. However, it is not specified if the cue hits parallel to the surface, so this assumption may affect the accuracy of the calculation.
  • #1
bluejay1
5
0

Homework Statement


A cue ball is hit 4.5 cm above the horizontal surface uk = 0.35 it is on.
The ball is 6 cm in diameter and has a mass of 250 g. It is hit
by a cue stick with an average force of
6000 N during a contact time of 20 usec.

(a) What is the ball’s speed after it is hit?

Homework Equations



F=Ma
x=x0+v0xt+1/2at^2

The Attempt at a Solution


I can't figure out the effect being hit above the equator has and how to incorporate it?
Thanks
 
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  • #2
It sounds like they want you to take into account the torque on the cue ball due to the fact that it was hit off center. I guess you assume that the cue does not slip and that it hits parallel to the horizontal surface, but it doesn't actually say that, so I'm just guessing.
 
  • #3
for your question. I would approach this problem by first breaking it down into smaller, more manageable parts. Let's start with the basic equations of motion, which you have already listed:

F=Ma (Newton's Second Law)
x=x0+v0xt+1/2at^2 (Equation of motion)

We also need to consider the coefficient of kinetic friction, uk, which is given as 0.35 in this problem. This value represents the amount of friction between two surfaces in motion. In this case, it is the friction between the cue ball and the surface it is rolling on.

Next, we need to think about the initial conditions of the cue ball. It is hit 4.5 cm above the horizontal surface, which will affect its initial velocity and trajectory. We also know the diameter and mass of the ball, which will be important for calculating its final speed.

Now, let's go through the steps to solve this problem:

1. Determine the initial velocity: Since the cue ball is hit by a cue stick with an average force of 6000 N during a contact time of 20 usec, we can use the equation F=Ma to calculate the initial acceleration of the ball. We know the mass of the ball is 250 g, so we can rearrange the equation to solve for acceleration: a=F/m = 6000 N / 0.25 kg = 24000 m/s^2. Now, we can use the equation of motion, x=x0+v0xt+1/2at^2, to solve for the initial velocity (v0) of the ball.

2. Account for the friction: Since the ball is rolling on a surface, we need to take into account the friction between the ball and the surface. We can do this by using the equation Ff=ukFn, where Ff is the force of friction, uk is the coefficient of kinetic friction, and Fn is the normal force (equal to the weight of the ball, mg). We can then subtract this force from the initial force (F) to get the net force acting on the ball.

3. Calculate the final speed: Now that we have the initial velocity and the net force acting on the ball, we can use the equation x=x0+v0xt+1/2at^2 to solve for the final velocity (v) of the ball.

By following these steps, we can calculate
 

What is cue ball rolling motion?

Cue ball rolling motion refers to the movement of a cue ball on a pool table when it is struck by a cue stick. It is a combination of linear and rotational motion.

What factors affect the cue ball's rolling motion?

The speed and direction of the cue stick, the angle at which it strikes the cue ball, and the surface of the pool table are all factors that can affect the cue ball's rolling motion.

How does friction impact the cue ball's rolling motion?

Friction between the cue ball and the pool table can cause the ball to slow down and change direction. The type and condition of the pool table's felt can greatly affect the amount of friction present.

Can the cue ball's rolling motion be predicted?

Yes, the cue ball's rolling motion can be predicted using mathematical equations and principles of physics. Factors such as the initial speed and direction of the cue ball, the mass and diameter of the ball, and the coefficient of friction between the ball and the table can all be used to calculate its trajectory.

How does spin on the cue ball affect its rolling motion?

Spin, or angular momentum, on the cue ball can greatly impact its rolling motion. It can cause the ball to curve or swerve, depending on the direction and amount of spin applied. This is often used in advanced pool shots to achieve desired results.

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