As part of a physics experiment, you stand on a bathroom scale in an elevator. Though your normal weight is 690 N, the scale at the moment reads 588 N.
(a) Is the acceleration of the elevator upward, downward, or zero?
(b) Calculate the magnitude of the elevator's acceleration.
m/s2
(c) What, if anything, can you say about the velocity of the elevator?
Explain.
please I need help. Thanks
2 answers
You don't have to give me the answer but explaining a way to get there would help
Weight is the force with which the object presses the stationary support. Weight may be less or greater than the force of gravity (mg) in dependence on the downward or upward motion, => Weight = N, but directed in the opposite direction
vector (ma)= vector (mg)+vector( N)
for upward motion: -ma=mg-N
N=ma+mg
for downward motion: ma=mg-N
N= mg –ma - this is the given case
mg=690 N, N=588N, m=mg/g=690/9.8=70.4 kg
588 =690 - ma
a=( 690-588)/70.4= 1.45 m/s²
vector (ma)= vector (mg)+vector( N)
for upward motion: -ma=mg-N
N=ma+mg
for downward motion: ma=mg-N
N= mg –ma - this is the given case
mg=690 N, N=588N, m=mg/g=690/9.8=70.4 kg
588 =690 - ma
a=( 690-588)/70.4= 1.45 m/s²
3 answers