The discussion revolves around a problem involving Newton's second law, specifically focusing on a crate sliding in the back of an accelerating truck. Participants are exploring the dynamics of the system, including free body diagrams and the forces acting on both the truck and the crate.
Several participants have provided guidance on the need for clear diagrams and the application of Newton's laws. There is an ongoing exploration of the forces involved, particularly regarding friction and acceleration, with some participants expressing uncertainty about their understanding and the correct approach to the problem.
Participants note that the problem lacks specific information about the coefficient of friction and that assumptions about the nature of the forces acting on the truck and crate are being debated. The discussion also highlights the importance of Newton's third law in analyzing the forces between the crate and the truck.
Here's a clue:Franklie001 said:Ok so do i need to consider the mass of the crate on the truck as whole so (mass of the truck + mass of the crate) what about the air forces (Fa1 and Fa2) do i need to add them too, or are they considered as internal forces?
Sadly that doesn't look quite right. Did you remember the air resistance on the crate?Franklie001 said:I've used the simultaneous equations and i 've got for the acceleration ax= 0.39 m/s^2 and for the force of friction f= -880N
Is that right?
I get a different answer. Did you remember the air resistance on the crate?Franklie001 said:So if the friction force is 944N i have an equal and opposite friction force acting on the crate.
Therefore the second solution is given already Ff=944N.
And the coefficient is 0.043
Well done. But you may have a rounding error. I got the friction force to be 1027.45N which rounds to 1030N.Franklie001 said:I've got Friction force = 1040N
and coefficient of kinetic friction u = 0.048