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Part

C

Suppose

a

person

with

a

weight

of

686

N

is

in

an

elevator

which

is

ascending

at

a

constant

rate

of

1.0

m/s

and

speeding

up

at

a

rate

of

3.0

m/s

{color:black}^2^{color}. What is the

². What is the person's

apparent

weight?

h4. Solution *System, Interactions and Model:* As in Part A. *Approach:* The free body diagram and form of Newton's 2nd Law is the same as in Part A, except that the relative size of the forces will be different. We can see this by writing Newton's 2nd Law for the y-direction: {latex}\begin{large}\[ N = ma_{y} + mg \]\end{large}{latex} This time, however, the acceleration is positive (_a_~y~ = + 3.0 m/s{color:black}^2^{color}) giving: {latex}\begin{large}\[ N = \mbox{896 N} \] \end{large}{latex} {tip}Upward acceleration increases the perceived weight.{tip}

Solution