Throwing ball out of a moving car

  • Thread starter cashmoney805
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In summary, the ball is moving at 40m/s when it leaves the passenger's hand and it has moved approximately 0m relative to the bystander at that moment.
  • #1
cashmoney805
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Homework Statement


A car is moving at 25m/s. A passenger, 1.5 m from the ground, can throw a ball at a max speed of 15 m/s and throws the ball out the window as he passes a bystander on the sidewalk. How fast is the ball moving when it leaves the passenger's hand and how far does the ball move relative to the bystander?


Homework Equations


For X component:
distance = velocity * time

For Y component:
x(f) = x(i) +v(i) + .5at2


The Attempt at a Solution


I believe that, relative to the bystander, the ball is moving at 40m/s. You can figure out the amount of time it takes the ball to reach the ground by solving for t for the Y component equation.
x(i) and v(i) = 0
a = g = 9.8m/s2
x(f) = 1.5m
solve, t = 0.55s

Now you just solve for the x component:
v = 40m/s
t = 0.55s
X = 22m

Is this correct? Thanks for the help.
 
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  • #2
Looks good!:approve: (assuming he throws the ball in the same direction as the car's movement)
 
  • #3
It seems you are answering for how far the ball moves before it hits the ground, but the question asks how far it has moved in relation to the pedestrian at the point of release. Wouldn't that make the distance the ball travels in relation to the pedestrian 0?
 
  • #4
The pedestrian is basically a fixed point. How would a moving object move zero distance in relation to a motionless one?
 
  • #5
CxStrike said:
The pedestrian is basically a fixed point. How would a moving object move zero distance in relation to a motionless one?


Extremely close to zero, in relation to the pedestrian, in that instant. I am probably wrong, that's why I'm asking.
 
  • #6
_Tully said:
Extremely close to zero, in relation to the pedestrian, in that instant. I am probably wrong, that's why I'm asking.
Do you have a formula/any numbers to explain why you're thinking this way?
 
  • #7
cashmoney805 said:
Do you have a formula/any numbers to explain why you're thinking this way?

Not at all, I'm hoping someone will pwn me with numbers so I can learn something here. It just seems logical that, in a snapshot in time, the ball hasn't moved in relation to the person, but I know logic is not the best thing to go on in these situations.

d = v * t, t = 0, or something extremely close to it, as the ball has not started it's journey yet (in relation to the pedestrian) as it has just arrived at it's starting point.
 
  • #8
_Tully said:
Not at all, I'm hoping someone will pwn me with numbers so I can learn something here. It just seems logical that, in a snapshot in time, the ball hasn't moved in relation to the person, but I know logic is not the best thing to go on in these situations.

d = v * t, t = 0, or something extremely close to it, as the ball has not started it's journey yet (in relation to the pedestrian) as it has just arrived at it's starting point.
Hm, you may be getting confused, thinking the question is asking "in the moment the passenger releases the ball, how far has it moved relative to the bystander."

If the question was worded something along the lines of "...how far has the ball moved relative to the bystander when it hits the ground" does that make it clearer?
 
  • #9
cashmoney805 said:
If the question was worded something along the lines of "...how far has the ball moved relative to the bystander when it hits the ground" does that make it clearer?

Hah well yea of course, I said that in my post, but the question is not written that way.

"How fast is the ball moving when it leaves the passenger's hand and how far does the ball move relative to the bystander?"

The and implies that 'leaving the passengers hand' and 'ball move relative to the bystander' are recorded at the same instant.

I understand the question is not actually asking this (I assume at least), but if it where asking the question that I am, am I correct? That's all I'm wondering.
 
  • #10
_Tully said:
Hah well yea of course, I said that in my post, but the question is not written that way.

"How fast is the ball moving when it leaves the passenger's hand and how far does the ball move relative to the bystander?"

The and implies that 'leaving the passengers hand' and 'ball move relative to the bystander' are recorded at the same instant.

I understand the question is not actually asking this (I assume at least), but if it where asking the question that I am, am I correct? That's all I'm wondering.
Oh, well yea. Haha.
 
  • #11
K, sweet, beers all around than. :smile:
 

1. What happens to the ball when thrown out of a moving car?

When a ball is thrown out of a moving car, it will continue to move in the same direction and speed as the car was moving. This is due to the law of inertia, which states that an object in motion will stay in motion unless acted upon by an external force.

2. Will the ball's trajectory change if the car is moving at different speeds?

Yes, the ball's trajectory will change based on the speed of the car. The faster the car is moving, the farther the ball will travel in the same amount of time. This is because the ball inherits the car's velocity when it is thrown out, and the higher the velocity, the longer the ball will stay in motion.

3. What factors can affect the distance the ball travels when thrown out of a moving car?

The distance the ball travels will depend on the initial velocity of the car, the angle at which the ball is thrown, and any external forces such as air resistance. The shape and weight of the ball can also play a role in the distance it travels.

4. Is it safe to throw a ball out of a moving car?

No, it is not safe to throw a ball out of a moving car. The ball can potentially hit other cars or pedestrians, causing harm to them. Additionally, the ball can bounce back into the car or hit the driver, causing a distraction and potentially leading to an accident.

5. How does the direction of the car's motion affect the ball's trajectory when thrown out?

The direction of the car's motion will affect the ball's trajectory in the same way that the car's speed does. If the car is moving forward, the ball will also move forward. If the car is turning, the ball's trajectory will follow the curved path of the turn. The angle at which the ball is thrown will also impact its trajectory in relation to the car's direction of motion.

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