# M1 help please- Connected particles

• Apr 16th 2010, 12:32 PM
fishkeeper
Im a little dubious on where to start this question.
Im not sure whether I have to create 2 simultaneous equations and then substitute one into the other, so im on here to ask for a few pointers.

Quote:

A car of mass 800kg is pulling a caravan of mass 1000kg along a straight, horizontal road. The caravan is connected to the car by means of a light, rigid tow bar. The car is exerting a driving force of 1270N. The resistances to the forward motion of the car and the caravan are 400N and 600N respectively.

Show that the acceleration of the car and caravan is 0.15ms-2
Any helpful guidance would be greatly appreciated and rep will be given!

thanks
• Apr 16th 2010, 12:47 PM
skeeter
Quote:

A car of mass 800kg is pulling a caravan of mass 1000kg along a straight, horizontal road. The caravan is connected to the car by means of a light, rigid tow bar. The car is exerting a driving force of 1270N. The resistances to the forward motion of the car and the caravan are 400N and 600N respectively.

Show that the acceleration of the car and caravan is 0.15ms-2
let T = force exerted by the tow bar on the car and caravan

net force on the car ...

Fnet = 1270 - (T+400)

800a = 1270 - (T+400)

net force on the caravan ...

Fnet = T - 600

1000a = T - 600

solve the system of equations for T and a