Same Speed for Ball Thrown from Moving Car?

In summary, the conversation discusses the concept of relative speed and how it applies to different objects. It is mentioned that there is a unique invariant speed, known as the speed of light, which follows a specific formula for all cases. This formula takes into account the relative velocity of two people, A and B, and the speed at which an object is thrown by A. It is noted that for any value of velocity, other than the speed of light, B will observe a different speed for the object. However, at lower velocities, the formula becomes practically indistinguishable from the traditional formula of u-v.
  • #1
Hepic
118
0
We have two people. A person(A) that is stadning and another(B) one who drives his car,so he has some velocitty. Let's say that the person B throw a photon from his car. Let's suppose that photon will hit down and will go up again. So both guys see the same speed.
But If instead of light,he throw a ball then both will see the same speed for the ball always?
 
Physics news on Phys.org
  • #2
No, there is a unique invariant speed, which we call the speed of light. According to relativity, there is one formula that covers all cases such as you describe:

Suppose B is moving at v relative to A. Suppose A throws 'something' at velocity u as measured by A. Then B sees the 'something' moving at:

(u-v)/ (1 - uv/c^2)

If you put u=c, you get c also for what B sees. For any other value of u, you get a different speed as observed by B. for u much less than c, this formula becomes empirically indistinguishable from u-v. But it is one formula for all cases.
 
  • Like
Likes 1 person

1. Does the speed of the car affect the speed of the ball thrown from it?

Yes, the speed of the car does affect the speed of the ball thrown from it. The ball will have the same horizontal velocity as the car, but its vertical velocity will be affected by the car's speed.

2. What factors contribute to the speed of the ball thrown from a moving car?

The speed of the car, the initial velocity of the ball, and the angle at which the ball is thrown all contribute to the speed of the ball thrown from a moving car.

3. Will the ball have the same speed if thrown in different directions from a moving car?

No, the speed of the ball will vary depending on the angle at which it is thrown from the moving car. The ball will have the greatest speed when thrown in the same direction as the car's motion.

4. How does air resistance affect the speed of the ball thrown from a moving car?

Air resistance will slow down the speed of the ball as it travels through the air. The impact of air resistance will be greater at higher speeds, so it will have a greater effect on the ball thrown from a fast-moving car.

5. Can the speed of the ball thrown from a moving car be calculated?

Yes, the speed of the ball can be calculated using the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. However, this calculation may be affected by variables such as air resistance and the car's motion, so the actual speed may vary slightly from the calculated value.

Similar threads

  • Special and General Relativity
2
Replies
45
Views
3K
  • Special and General Relativity
3
Replies
72
Views
4K
  • Special and General Relativity
Replies
6
Views
1K
  • Special and General Relativity
Replies
23
Views
816
  • Special and General Relativity
Replies
4
Views
1K
  • Special and General Relativity
3
Replies
87
Views
9K
  • Introductory Physics Homework Help
Replies
5
Views
230
  • Special and General Relativity
3
Replies
83
Views
7K
  • Special and General Relativity
Replies
10
Views
945
  • Special and General Relativity
2
Replies
57
Views
4K
Back
Top