Answer:
<h2>980000ft-lbs</h2>
Explanation:
Step one:
given data
mass of cable= 4lb/ft
mass of coal= 1000lb
dept of mine= 700ft
Step two:
Required
the work-done to lift the coal and the rope combined
Work-done to lift coal
Wc=1000*700= 700,000 lb-ft
Work-done to lift rope

substitute y=700 we have, since y=0 will result to 0

Answer:
A. It is made of tissues that can conduct electricity, a required function in a system.
Explanation:
The nervous system helps all the parts of the body to communicate with each other. It also reacts to changes both outside and inside the body. The nervous system uses both electrical and chemical means to send and receive messages.
Answer:
1.54 s
Explanation:
Considering that the legs constitute 16% of the total weight of the man then mass, 
The legs also constitute 48% of his height hence 
The moment of inertia of a cylinder rotating about a perpendicular axis at one end is
hence 
We also know that the period is given by 
Here, h=0.5H= 0.5*0.8784=0.4392 m
Taking g as 9.81 kg/m2 then

Answer:
The speed of the 8-ball is 2.125 m/s after the collision.
Explanation:
<u>Law Of Conservation Of Linear Momentum</u>
The total momentum of a system of masses is conserved unless an external force is applied. The momentum of a body with mass m and velocity v is calculated as follows:
P=mv
If we have a system of masses, then the total momentum is the sum of all the individual momentums:

When a collision occurs, the velocities change to v' and the final momentum is:

In a system of two masses, the law of conservation of linear momentum is simplified to:

The m1=0.16 Kg 8-ball is initially at rest v1=0. It is hit by an m2=0.17 Kg cue ball that was moving at v2=2 m/s.
After the collision, the cue ball comes to rest v2'=0. It's required to find the final speed v1' after the collision.
The above equation is solved for v1':




The speed of the 8-ball is 2.125 m/s after the collision.
The weight of anything in any place is
(mass of the thing) x (acceleration of gravity in that place).
-- On Earth, the acceleration of gravity is about 9.807 m/s²
Weight of 19 kg of mass is (19 kg) x (9.807 m/s²) = <em>186.3 newtons</em>
-- On the Moon, the acceleration of gravity is about 1.623 m/s²
Weight of the same 19 kg of mass is (19 kg) x (1.623 m/s²) = <em>30.8 newtons</em>