Posted by rav on Saturday, July 15, 2006 at 1:05pm.
A particle of mass m kg is acted on by two forces F1 and F2 with magnitudes 3root5 newtons and root5 newtons ad drections parallel to the vectors i+2j and i-2j respectively
The particle is initially at a position given by vector 2i+j
iv calculated the cartesian components of F1 and F2
F1 = 3i+6j
F2 = i 2j
iv also calculated the cartesian component of the total force F1+F2 = (3i+6j)+(i-2j) = 4i +4j
however the part im struggling on is that now the particle is of mass 1kg and is initially at rest, i have to use newtons 2nd law to write down an equation of motion and find the position of the particle after 1second.
so far iv tried:
therefore a = 4i+4j but then i dont know how to find the new posistion ...can anyonehelp thankz
New postion= oldposition +intialvelocity*time + 1/2 acceleration*time^2.
Technically, you should integrate to get this equation, but because acceleration is constant, the integration leads to the preceeding.
where acceleration= force/mass, and you have force and mass.
all the above of course is a vector equation, not messy at all. You can work the i,j components as separate equations, as the system is orthogonal. If needed, I can critique your work.
thankz iv worked it out
Assuming you have calculated the "a" vector correctly, just multiply it by t^2 to get the vector position change at time t. You do not have to add a term for (initial velocty vector) times t,, because the mass was initially at rest.
Add the position change vector to the initial position coordinates to get the new location.
I forgot about the factor (1/2) when calculating the position change due to acceleration. Bob Pursley's answer, posted just before mine, is correct
I have no clue.
Answer this Question
More Related Questions
- maths/physics - particle of mass m kilograms is acted on by two forces F and ...
- mechanics - A particle of mass 10 kg is acted on by a resultant force, F newtons...
- Physics - A particle is acted upon two forces given by the vector equations, F1=...
- physics - Two forces of magnitude 20 newtons and 25 newtons respectively act at ...
- math/physics - Forces with magnitudes of 2000 newtons and 900 newtons act on the...
- physics - A car with a mass of 1.2 × 103 kilograms starts from rest and attains ...
- Mechanics A level? - A particle P lies on a smooth horizontal surface. It is ...
- MATH116 - Two forces of magnitudes 60 Newtons and 80 Newtons make an angle of 30...
- Physics - Three forces are applied to a mass. Force 1: +3 Newtons Force 2: -3 ...
- Physics - A mass of 8 kg lies on a horizontal, frictionless floor. A force of 72...