Physics word prob.

[shooterman]

A rock Climber throws a small first aid kit to another climber who is higher up the mountain. The initial velocity of the kit is 11 m/s at an angle of 65 degrees above the horizontal. At the instant when the kit is caught, it is traveling horizontaly, so its vertical speed is zero. What is the vertical height between the two climbers?

Don't know where to start on the equation.
Should I start with the horizontal component?

 

[wjm11]

A rock Climber throws a small first aid kit to another climber who is higher up the mountain. The initial velocity of the kit is 11 m/s at an angle of 65 degrees above the horizontal. At the instant when the kit is caught, it is traveling horizontally, so its vertical speed is zero. What is the vertical height between the two climbers?

Don't know where to start on the equation.
Should I start with the horizontal component?

The horizontal component is irrelevant in this problem.

Find the vertical component of velocity. Assume the kit is being thrown straight up with only the vertical component. Calculate how high the kit would go.

Use (v final)^2 = (v initial)^2 + 2a(delta x)

a = -9.81 m/s^2

 

[shooterman]

To find vertical component is with Vv=Vsin theta am i right.
If so, then i would plug 11m/s into V or I have to find it myself?

 

[wjm11]

To find vertical component is with Vv=Vsin theta am i right.
If so, then i would plug 11m/s into V or I have to find it myself?

You are correct.

Vv = vsin theta = (11 m/s)(sin 65) = 9.97 m/s (approx.)

 

[shooterman]

ok then back to (v final)^2 = (v initial)^2 + 2a(delta x)
(0)^2 = (9.97)^2 + 2(-9.8)(x)
-99.4009 = -19.6x
x = 5.07 meters
correct.

 

[wjm11]

ok then back to (v final)^2 = (v initial)^2 + 2a(delta x)
(0)^2 = (9.97)^2 + 2(-9.8)(x)
-99.4009 = -19.6x
x = 5.07 meters
correct.

Looks good. Round to 5.1 m if significant figures is rqd.

PS. Re your "signature", one might consider trying to *improve* mankind rather than flipping mankind off. Just a passing thought. ;-)

 

[shooterman]

Sorry, I did not get you passing thought.
In what part of the signature has the meaning of this?

Well any ways I have anothrer Physics word prob.

The lob in tennis is an effective tactic when your opponent is near the net. It consists of lofting the ball over his head, forcing him to move quickly away from the net (see the drawing). Suppose that you loft the ball wiht an initial speed of 15.0 m/s, at an angle of 50.0 degrees above the horizontal. At this instant your opponent is 10.0m away from the ball. He begins moving away from you 0.30s later, hoping to reach the ball and hit it back at the moment that it is 2.10 m above its launch point. With what minimum average speed must he move? ( Ignore the fact that he cna stretch, such that his racket can reach the ball before he does.)