Solution :
Acceleration due to gravity of the earth, g 

Acceleration due to gravity at 1000 km depths is :




= 8.23 m/s
Acceleration due to gravity at 2000 km depths is :




= 6.73 m/s
Acceleration due to gravity at 3000 km depths is :



= 5.18 m/s
Acceleration due to gravity at 4000 km depths is :




= 3.64 m/s
Answer:
Explanation:
Given
mass of skier=60 kg
distance traveled by skier=75 m
inclination
speed (v)=2.4 m/s
as the skier is moving up with a constant velocity therefore net force is zero

Force applied by cable

work done

(b)Power

Answer:
F= 5.71 N
Explanation:
width of door= 0.91 m
door closer torque on door= 5.2 Nm
In order to hold the door in open position we need to exert an equal and opposite torque, to the door closer torque, on the door.
so wee need to exert 5.2 Nm torque on the door.
If we want to apply minimum force to exert the required torque we need to apply force perpendicularly on the door knob (end of door) so that to to greater moment arm.
T= r x F
T= r F sin∅
F= T/ (r * sin∅)
F= 5.2/ (0.91 * 1)
F= 5.71 N