Answer: Advanced technologixal machines
Explanation: such as big cranes, multiple workers helping creat said structure, and big bull dozers
Answer:
Answer for the question :
"the two boxcars A and B have a weight of 20 000 Ib and 30 000 Ib, respectively. If they coast freely down the incline when the brakes are applied to all the wheels of car A causing it to skid, determine the force in the coupling C between the two cars. The coefficient of kinetic friction between the wheels of A and the tracks is μk=0.5. The wheels of car B are free to roll. Neglect their mass in calculation."
is explained in the attachment.
Explanation:
Answer:
In Btu:
Q=0.001390 Btu.
In Joule:
Q=1.467 J
Part B:
Temperature at midpoint=274.866 C
Explanation:
Thermal Conductivity=k=30 (Btu/hr)/(ft ⋅ °F)= 
Thermal Conductivity is SI units:

Length=20 cm=0.2 m= (20*0.0328) ft=0.656 ft
Radius=4/2=2 mm =0.002 m=(0.002*3.28)ft=0.00656 ft
T_1=500 C=932 F
T_2=50 C= 122 F
Part A:
In Joules (J)

Heat Q is:

In Btu:

Heat Q is:

PArt B:
At midpoint Length=L/2=0.1 m

On rearranging:


so people dont die whaddya think?
Answer:
Use a screw or corkscrew. Screw it into the eraser, then pull.