Calculating Relative Velocity of Grenade in Moving Vehicles

AI Thread Summary
The discussion revolves around calculating the relative velocity of a grenade thrown from a moving car in an action-adventure film scenario. The hero's car travels at 91.0 km/h, while the enemy's car is moving at 106 km/h, positioned 14.5 meters ahead. The key problem involves determining the initial velocity of the grenade relative to the hero, thrown at a 45-degree angle, and its velocity relative to the Earth. A participant highlights the importance of using initial positions for both cars to solve the problem effectively. The inclusion of the 14.5 meters is crucial for calculating the initial velocity needed for the grenade to reach the enemy's car.
anubis01
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Homework Statement


In an action-adventure film, the hero is supposed to throw a grenade from his car, which is going 91.0 km/h, to his enemy's car, which is going 106 km/h. The enemy's car is 14.5 m in front of the hero's when he let's go of the grenade.

a)If the hero throws the grenade so its initial velocity relative to him is at an angle of 45 above the horizontal, what should the magnitude of the initial velocity be?

b)Find the magnitude of the velocity relative to the earth.



Homework Equations


Vh/r=90 km/h
Ven/r=110 km/h
Vh/En=??


The Attempt at a Solution



a)I have no real idea on how to proceed with this problem. The real thing that is confusing me is the inclusion of the 14.5m and it can be used in calculating the initial velocity.

Any help is as always much appreciated.
 
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anubis01 said:
The real thing that is confusing me is the inclusion of the 14.5m and it can be used in calculating the initial velocity.

Hi anubis01! :smile:

You need to use x1 for one car and x2 for the other car, and x1(0) = 0 while x2(0) = 14.5. :wink:
 
ah I see, I get it now. Thank you for the help.
 

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