AuthenticD3mon and I talked it over and agreed that
natural gas is the least polluting fossil fuel.
(See comments under his answer.)
Answer:
The work done to get you safely away from the test is 2.47 X 10⁴ J.
Explanation:
Given;
length of the rope, L = 70 ft
mass per unit length of the rope, μ = 2 lb/ft
your mass, W = 120 lbs
mass of the 70 ft rope = 2 lb/ft x 70 ft
= 140 lbs.
Total mass to be pulled to the helicopter, M = 120 lbs + 140 lbs
= 260 lbs
The work done is calculated from work-energy theorem as follows;
W = Mgh
where;
g is acceleration due gravity = 32.17 ft/s²
h is height the total mass is raised = length of the rope = 70 ft
W = 260 Lb x 32.17 ft/s² x 70 ft
W = 585494 lb.ft²/s²
1 lb.ft²/s² = 0.0421 J
W = 585494 lb.ft²/s² = 2.47 X 10⁴ J.
Therefore, the work done to get you safely away from the test is 2.47 X 10⁴ J.
Answer:
Mass of receiver is 92 kg
Explanation:
We have given mass of tackler 
Let the mass of receiver is 
When tackler moving alone velocity is 
m/sec
And when tackler and receiver is together velocity is 
= 2.5 m/sec
So from conservation of momentum
So mass of receiver is 92 kg
The density is 4.76 gcm^-3
and if mass is in kg then density is equal to 4.76*10^-3
