Answer:
50
Explanation:
The mechanical advantage of a machine is given by

where
is the output force
is the input force
For the crowbar in this problem,
is the force in input applied by the worker
is the force that the machine must apply in output to overcome the resistance of the window and to open it
Substituting into the equation, we find

Answer:
1- b: 2- a : 3- c : 4- d
Explanation:
it starts 2 move away from strting point, then no motion, then moves toward the start, the slows up.
Answer:
space , small amount of gravity is found in the space ,infact we can say that there is no gravity in the space
That certain change from that ecosystem will require 50 years or longer because big ecosystems need a long time to restablize the living ecosystem.