- #1
Ripe
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Hi,
I've very recently begun physics self-teaching as I used to find it boring and thus avoided it as a subject but now find it increasingly interesting. Nevertheless, I'm having some problems regarding questions on Newton's First Law. One of the questions in the book I'm using says the following:
"A 455N crate is being pulled at constant velocity by a force (F) directed at 30 degrees to the horizontal. The frictional force on the crate is 1163N. What is the magnitude of the pulling force?"
Now, since it's being pulled at constant velocity, that should mean that the net force is 0. However, in order to get the same answer as in the mark scheme, one has to equate Fx (i.e. the x-axis component of F) to the same magnitude as the friction force and then use cos30=Fx/F to find the answer. The problem is that I don't see how the net force is 0 in this case. The fact that Fx is of the same magnitude, but opposite, to the friction force, wouldn't that mean that the resultant force is the Fy component, and thus not 0?
I would appreciate it if someone could shed some light on this matter!
I've very recently begun physics self-teaching as I used to find it boring and thus avoided it as a subject but now find it increasingly interesting. Nevertheless, I'm having some problems regarding questions on Newton's First Law. One of the questions in the book I'm using says the following:
"A 455N crate is being pulled at constant velocity by a force (F) directed at 30 degrees to the horizontal. The frictional force on the crate is 1163N. What is the magnitude of the pulling force?"
Now, since it's being pulled at constant velocity, that should mean that the net force is 0. However, in order to get the same answer as in the mark scheme, one has to equate Fx (i.e. the x-axis component of F) to the same magnitude as the friction force and then use cos30=Fx/F to find the answer. The problem is that I don't see how the net force is 0 in this case. The fact that Fx is of the same magnitude, but opposite, to the friction force, wouldn't that mean that the resultant force is the Fy component, and thus not 0?
I would appreciate it if someone could shed some light on this matter!