Newtons first law of motion is also known as the law of inertia
Answer:
a.14 s
b.70 s
Explanation:
a.Let the sidewalk moving in positive x- direction.
Speed of sidewalk relative to ground=
Speed of women relative to sidewalk=v=1.5m/s
The speed of women relative to the ground

Distance=35 m
Time=
Using the formula
Time taken by women to reach the opposite end if she walks in the same direction the sidewalk is moving=
b.If she gets on at the end opposite the end in part (a)
Then, we take displacement negative.
Speed of sidewalk relative to ground=
Speed of women relative to sidewalk=v=-1.5 m/s
The speed of women relative to the ground=
Time=
Hence, the women takes 70 s to reach the opposite end if she walks in the opposite direction the sidewalk is moving.
Electromagnets can be turned off, this makes it easier to release things from the magnetic field.
Hope this helps :)
Answer:
160N
Explanation:
Moments must be conserved - so.


Mechanical advantage of a machine is the ratio of the output force over the input force or M=Fo/Fi. Since M=1, Fi=Fo, or the input force is equal to the output force. This means that to raise the refrigerator that weighs 900 N, we need the same input force of 900 N, or Fo=Fi=900 N.