physics law of motion problem?

Question

the weight of the block o the table is 422 N and that of the hanging block is 185 N. Ignoring all frictional affects and assuming the pulley to be massless, find (a) the acceleration of the two blocks and (b) the tension in the cord.

I wasn't sure how to work this problem..
thanks

Answer 1

What makes you believe that the system will even move? The 422 N block will just rest on the table.

If we change them places then
Let F1=185N
and F2=422N then The total force acting on the blocks is
Ft= F2-F1
and since F=ma

a= Ft/(m1+m2)
where m1+m2= (F1+F2)/g

F(tension)= m1 a - F1

or
F(tension)= F2 - m2 a

Answer 2

The way I attack such problems is to look at one piece at a time.

First, look at the forces acting on the hanging weight. There are two:
* Its weight (185N down)
* The tension in the rope pulling up (call it "T"--don't know how much that is yet, but don't worry about that.)

Now look at the forces acting on the weight resting on the table:
* Its weight (down) and pressure of table (up). But those two cancel each other out, so forget about 'em.
* The tension in the rope pulling sideways (amount is "T" -- same T as before!)

Now the nice thing is that the rope tension T is the same on both blocks (that's always true of (weightless) ropes). This fact will help you.

Aha! You can now write an equation for the acceleration of the block on the table. (Hint: use F=ma. Hint: the equation will have "T" in it.)

Aha! You now have an equation for how fast the hanging weight is accelerating (why? Becuase it must be accelerating at the same rate as the table-sitting block (because they're connected by a rope!))

Aha! You can also write a _different_ equation for the hanging weight's acceleration. This one will ignore the other weight; it will just be in terms of the total force (up & down) and the weight's mass.

So, now you have two equations representing the acceleration of the hanging weight:

a = (something)
a = (something else)

Now combine the two: (something) = (something else). That will give you an equation that lets you figure out how much "T" is.

Once you've figured out "T", you can then figure out how much "a" is.

Answer 3

1. Set up a static diagram
2. Identify all of the forces involved. Without friction all you have left is mass and gravity.
3. Determine angles and using trig figure out how much force is working in hwat direction.
4. Use the equation F = m * a

Answer 4

If forces act interior an identical direction then you definately upload them, in the event that they act in opposite guidelines, you subtract them to paintings out the nett stress. in this occasion you have a cart of 0.4kg + a fan 0.3kg + a fan 0.3kg = entire of 1kg. stress to left = 0.7 N stress to desirable = 0.8 N Nett stress = 0.8 - 0.7 = 0.one million N to the the final option!! making use of Newtons 2d regulation-: stress = Mass * Acceleration 0.one million = one million * Acceleration 0.one million / one million = Acceleration = 0.one million ms^-2 So the cart will enhance up at 0.one million ms^-2 to the the final option!!!!