# Force and angle

## Homework Statement

how do we measure 2 forces on an angle?

let's say we get an object that is moving ( a rocket?)

the gravity pull it down while the rocket engineer gives more force.

however to reach the highest height, we shot it at 90 degree(horizon). and also at that time, the gravity and engineer force are facing each other in a straight line.

then what would happen if 2 forces are meet in different angles???

such as 45 degree?

## Homework Equations

I know the equations for forces, however what i am trying to understand is what is the effect of angle on forces?

## The Attempt at a Solution

google get a bunch of useless inf...

## Answers and Replies

jgens
Gold Member
Forces are what are called vector quantities and need to be resolved into their respective components to analytically solve for the specific effect.

do you know a good equation for it?

You would draw a diagram representing the vector quantities, and solve for the resultant vector. Usually law of sine and cosine are helpful

Delphi51
Homework Helper
Newton, I must tell you about an interesting demonstration I used to do for all my physics students. I had this light bulb hanging from the ceiling via an electromagnet. At the side of the room, at the same height as the bulb, I had a spring gun that could shoot a ball bearing toward the bulb. When the spring was released to shoot the bearing horizontally, the current to the electromagnet was cut so the bulb fell at the same time.

The interesting thing was that the bulb and the ball fell the same way so the ball always hit the bulb! Even when I changed the stretch on the spring so it shot the ball faster or slower.

It seems that the horizontal motion does not affect the vertical motion!

When you shoot a rocket at an angle, you just figure out the horizontal and vertical parts of the motion separately, because one does not affect the other.

PS I must confess that my gun did not shoot straight so the ball usually passed on one side or the other of the bulb. But the height was right!

Newton V, good basic question. As you may have learned from your intro class, forces are represented by vectors. This is because they have magnitude (strength) and direction. What you should do
1) draw a picture of the problem.
2) Draw the force diagram,
3) break the forces into components, in this case the horizontal and vertical directions,
4) solve for your net force by adding the forces together in their component forms
5) write your answer in component form using either vector notation or magnitude and angle form.

** You will need a to use some trig, but don't be afraid. They're just homework probelms.

The interesting thing was that the bulb and the ball fell the same way so the ball always hit the bulb! Even when I changed the stretch on the spring so it shot the ball faster or slower.

It seems that the horizontal motion does not affect the vertical motion!
QUOTE]

wait i do not fully understand... how come the bulb and ball fall at same way? didn't the ball hit the stone?

Delphi51
Homework Helper
Fall the same way - both ball and bulb are always at the same height. They have the same vertical motion.

Do you have a video or some kind picture? i still don't get it... so they fall at the same spot? or they just meet at same height?

Delphi51
Homework Helper
Sorry, no video. Imagine the bulb falling from the ceiling in the middle of the room. The ball is shot from the side of the room toward the bulb. They meet just above a garbage can so the glass from the bulb is neatly disposed of.

oh i get it now, i thought you mean the ball hit the bulb before it fall...