- #1
hey123a
- 37
- 0
Homework Statement
Two 5-N boxes are attached to opposite ends of a spring scale and suspended from pulleys as shown. In my drawing, the xxxxx represents the scale in the midde.
...|o\-------xxxxxx-------/o|
...|...\...../...|
...|...\______________/ ...|
...|...|_____________|...|
[5N]......[5N]
What is the reading on the scale?
a) 0N
b) 2.5N
c) 5N
d) 10N
e) 25N
Relevant equations
F = Ma
The attempt at a solution
Well since there is 5N on both sides I would expect that the reading on the scale is zero because i would assume that it stays at equilibrium. Apparently I'm wrong on that so any hints would be nice
2. Homework Statement
A 4kg block is connected by means of a massless rope to a 2-kg block as shown in the figure. Complete the following statement: If the 4kg block is to begin sliding, the coefficient of static friction between the 4kg block and the surface must be
....[...].-------oo
________[4kg]_____/...|
|......|...|
|________________|..[2kg]
a) less than zero
b) greater than 2
c) greater than 1, but less than 2
d) greater than 0.5, but less than 1
c) less than 0.5, but greater than zero
Relevant equations
F = Ma
Fs = uN
The attempt at a solution
Since both blocks are connected I would assume that they accelerate together at the same rate
So f = (4kg + 2kg)a
F = 6a
if the 4kg block begins sliding then the system is achieving an acceleration that would overcome the force of static friction, but Fsmax would equal uN
Fs = uN
Fs = u(mg)
Fs = u(6x9.8)
Fsmax = u58.8
and now here I'm stuck and i don't know what to do