Question

An elevator starts from rest with a constant
upward acceleration andmoves 1m in the first
1.8 s. A passenger in the elevator is holding a
8.7 kg bundle at the end of a vertical cord.
What is the tension in the cord as the ele-
vator accelerates? The acceleration of gravity
is 9.8 m/s2 .
Answer in units of N

Answer 1

Ok so we know
Mass=M=8.7kg
Distance=d=1 meter
Time=t=1.8 seconds
Gravity=g=9.8m/s^2
And the formula for Acceleration I get by the formula for
Distance=D=1/2at^2
so moving things around I get
Acceleration=A=2d/t^2 =(2*1m)/(1.8s)^2 = 2m/2.34s^2 = .62m/s^2
So to find then plug in to T=m(g+a)
8.7kg(9.8m/s^2+.62m/s^2)=8.7(10.42)=90.63 kg*m/s^2
Which is 90.63N ??? Correct?

Answer 2

right wrong???? any thoughtS?

Answer 3

looks good

Answer 4

k. its probably wrong somehow but thanks....

Answer 5

ok it was right. someone needs to give ME a medal...

Answer 6

hvn't u studied about pseudo force.?

Answer 7

If you insist that you have made a mistake, perhaps you are referring to this line
Acceleration=A=2d/t^2 =(2*1m)/(1.8s)^2 = 2m/2.34s^2 = .62m/s^2

where you have 1.8^2 = 2.34 Of course 1.8*1.8= 3.24. However, 2.34 is clearly a typo because you get 0.62 which is 2/3.24 (not to mention the obvious swap of digits 2 and 3)