# The Naked Scientists Forum

### Author Topic: How do forces resolve?  (Read 1198 times)

#### LetoII

• Full Member
• Posts: 64
##### How do forces resolve?
« on: 20/09/2012 18:27:17 »
if an object is traveling forward in a straight line and experiences a sideways force both left and right of equal strenght. does this cause this speed in the forward direction to lower?

i think an example would be the following
If a car is going forward and 2 kids on the backseat throw a ball to eachother of equal weight at the same time. does this lower the speed of the car in the forward dimension?
« Last Edit: 20/09/2012 18:29:31 by chris »

#### chris

• Neilep Level Member
• Posts: 5336
• Thanked: 65 times
• The Naked Scientist
##### Re: How do forces resolve?
« Reply #1 on: 20/09/2012 18:30:50 »
The applied forces are opposite to one another and at right angles to the direction of movement of the object; therefore they have no component in the direction of travel and therefore there is no net force on the object so it's trajectory will remain unchanged.

#### lightarrow

• Neilep Level Member
• Posts: 4586
• Thanked: 7 times
##### Re: How do forces resolve?
« Reply #2 on: 20/09/2012 19:16:01 »
the speed wouldn't vary even if the forces were parallel to the trajectory, however.

#### syhprum

• Neilep Level Member
• Posts: 3818
• Thanked: 19 times
##### Re: How do forces resolve?
« Reply #3 on: 20/09/2012 20:03:01 »
If the car was accelerating the rate of acceleration would be increased while the ball was airborne but would fall back as soon as the ball was caught.

#### lightarrow

• Neilep Level Member
• Posts: 4586
• Thanked: 7 times
##### Re: How do forces resolve?
« Reply #4 on: 21/09/2012 16:27:29 »
If the car was accelerating the rate of acceleration would be increased while the ball was airborne but would fall back as soon as the ball was caught.
Ah, yes, with the example it's true, I intended the forst part of the OP's question, with two forces of equal strenght which are opposite (without specifying the time, it means that they always cancel each other).

#### yor_on

• Naked Science Forum GOD!
• Posts: 11987
• Thanked: 4 times
• (Ah, yes:) *a table is always good to hide under*
##### Re: How do forces resolve?
« Reply #5 on: 22/09/2012 02:02:56 »
Well assuming two walls pressuring at the car from opposite sides it should slow down. A pity you wrote that clarifying example. The discussion could have became much livelier without :)

#### The Naked Scientists Forum

##### Re: How do forces resolve?
« Reply #5 on: 22/09/2012 02:02:56 »