What you need to do here is a little bit of research, namely into what smartphones are made of. Once you find each component, you can find out what elements are in each component, and from there simply find whatever elements are not radioactive.
Answer:
Explanation:
a) the free body diagram of the lower pulley would have two force vectors of equal magnitude acting upward and the block weight acting downward. These must balance so 2F = Wt
F = 262/2 = 131 N
b) as the force needed is half of the block weight, the mechanical advantage is 262 / 131 = 2
c) with a mechanical advantage of 2, he would have to pull twice the distance of block motion or 2(3.00) = 6.00 m
d) W = Fd = 131 N(6.00 m) = 786 J
which is the same as the increase in potential energy of the block
e) W = mgh = 262(3.00) = 786 J
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Answer:
Ff = 19.6 N
Explanation:
So since its saying whats the minimum F to move the block, we will use static friction (0.5).
We will use the equation for force of friction, which is Ff = uFn
Ff = (0.5)(4)(9.8)
Ff = 19.6 N
this is the minumum force needed to move the block, as that is the frictional force. You would need to apply a minimum force of 19.6 N to move the block
Geometric shape tools
Hope this helps :)