Re: Hero velocity problem

let = time (in sec) the grenade is a projectile

position of the enemy car in meters ...

position of the projectile ...

... where is the x-component of grenade's initial velocity

since the idea is for the projectile and enemy car to be at the same place at the same time ...

in the y-direction, the projectile's total displacement is zero ...

... where is the y-component of the grenade's initial velocity.

solving for ...

since the launch angle is , , so .

... substitute for in the equal position equations and solve for

Re: Hero velocity problem

If vy=vx wouldn't vx be 0 then?

Re: Hero velocity problem

Quote:

Originally Posted by

**Oldspice1212** If vy=vx wouldn't vx be 0 then?

how did you arrive at that conclusion?

Re: Hero velocity problem

I have no clue what I'm doing :(. How do you get the relative velocity?!

Re: Hero velocity problem

Quote:

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

I've set up the necessary equations for you to solve for the magnitude of the grenade's initial velocity. If you cannot follow the proposed solution, then I advise you have a face-to-face consultation with your instructor.

Re: Hero velocity problem

Re: Hero velocity problem

Thought I had it, guess not, I got 54.7 km/h?