The height at which the mass will be lifted is; 3 meters
<h3>How to utilize efficiency of a machine?</h3>
Formula for efficiency is;
η = useful output energy/input energy
We are given
η = 60% = 0.6
Input energy = 4 KJ = 4000 J
Thus;
0.6 = useful output energy/4000
useful output energy = 0.6 * 4000
useful output energy = 2400 J
Work done in lifting mass(useful output energy) = force * distance moved
Useful output energy = 800 * h
where h is height to lift mass
Thus;
800h = 2400
h = 2400/800
h = 3 meters
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Answer:
D
Explanation:
Most electric vehicles can go at least 100.....few, if any, can go 400 or more on a single charge
Answer:
275 MPa
Explanation:
Regardless of what it is holding, the stiffness of a bolt depends on its own material properties and geometry.
The stiffness is:

I assume this one is made of steel, because regular bolts are steel.
The Young's modulus for steel is E = 210 GPa
The longitude is given. (But note that in a real application you have to consider the length up to the nut.)
The section is (using the nominal diameter of 10 mm)

Then:
