Determining Impact Time of a Ball given Launch Velocity

In summary, when comparing two launch velocities with the same vertical component, the one with a higher horizontal component will result in a shorter time for the ball to reach the wall. The horizontal component is the only one that affects the time of travel in projectile motion.
  • #1
rocomath
1,755
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You throw a ball with launch velocity of [tex]\overrightarrow {v_i}=(3m/s)\widehat{i}+(4m/s)\widehat{j}[/tex] toward a wall, where it hits at height [tex]h_1}[/tex] in time [tex]t_1[/tex] after the launch. Suppose that the launch velocity were, instead, [tex]\overrightarrow {v_i}=(5m/s)\widehat{i}+(4m/s)\widehat{j}[/tex].

Would the time taken by the ball to reach the wall be greater than, less than, or equal to [tex]t_1[/tex]?

I thought that the horizontal component played no role in a projectile motion? Answer is less than, I would have chosen equal to. Should I compute the magnitude in order to convince myself other wise (course it would be greater for the 2nd).
 
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  • #2
I thought that the horizontal component played no role in a projectile motion?

That's the ONLY component that matters here. Horizontal component is faster, gets there faster. When attempting to figure out how long it takes the ball to travel a horizontal distance, you're only interested in how fast it's going horizontally

Edit: So to make it even clearer, if the problem had the first case being 3 m/s horizontal and 45 sextillion m/s vertically, and the second case is 4 m/s horizontal but 3 nanometers/s vertical, answer is the same(EDIT and by the same I mean the same answer as the original question, which is the second one gets there faster)
 
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  • #3


I would like to provide a detailed explanation for the given scenario.

Firstly, it is important to understand that the launch velocity of a ball affects both its horizontal and vertical motion. The horizontal component determines the distance the ball will travel while the vertical component determines the height it will reach.

In the given scenario, the launch velocity of the ball is different in both cases. The first launch velocity is (3m/s) in the horizontal direction and (4m/s) in the vertical direction, while the second launch velocity is (5m/s) in the horizontal direction and (4m/s) in the vertical direction.

Now, when the ball is thrown towards the wall, it will follow a parabolic path due to the influence of gravity. The time taken by the ball to reach the wall will depend on the height at which the ball is thrown, the launch velocity, and the angle at which it is thrown.

In this case, the launch velocities are different, and therefore, the time taken by the ball to reach the wall will also be different. The ball with a higher launch velocity of (5m/s) will cover a greater horizontal distance in the same amount of time compared to the ball with a launch velocity of (3m/s). This means that the ball with a higher launch velocity will reach the wall in a shorter amount of time compared to the ball with a lower launch velocity.

In other words, the time taken by the ball to reach the wall will be less than t_1 when the launch velocity is increased from (3m/s) to (5m/s).

To further convince yourself, you can calculate the magnitude of the launch velocity in both cases. The magnitude of the launch velocity for the first case is √(3^2+4^2)=5m/s, while for the second case it is √(5^2+4^2)=6.4m/s. This clearly shows that the magnitude of the launch velocity is greater in the second case, indicating that the time taken by the ball to reach the wall will also be less.

In conclusion, the time taken by the ball to reach the wall will be less than t_1 when the launch velocity is increased from (3m/s) to (5m/s). Therefore, the correct answer is less than t_1.
 

Related to Determining Impact Time of a Ball given Launch Velocity

1. How is the launch velocity of a ball determined?

The launch velocity of a ball is determined by measuring the speed at which the ball is released or launched from its starting point. This can be done using a radar gun or by using video analysis techniques to track the ball's movement.

2. What factors affect the impact time of a ball?

The impact time of a ball can be affected by several factors, including the launch velocity, the angle of launch, air resistance, and the composition and shape of the ball. Other factors such as gravity and wind can also play a role in determining the impact time.

3. How can the impact time of a ball be calculated?

The impact time of a ball can be calculated using the equation t = (2v*sinθ)/g, where t is the time of impact, v is the launch velocity, θ is the angle of launch, and g is the acceleration due to gravity. This equation assumes ideal conditions and neglects air resistance.

4. Why is it important to determine the impact time of a ball?

Determining the impact time of a ball is important for a variety of reasons, including understanding the physics of the ball's motion, predicting the trajectory of the ball, and ensuring safety in sports and other activities where balls are involved.

5. Can the impact time of a ball be affected by external factors?

Yes, the impact time of a ball can be affected by external factors such as air resistance, wind, and the surface on which the ball lands. These factors can alter the trajectory and speed of the ball, ultimately affecting the impact time.

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