From the law of conservation of momentum
m1u1+ m2u2= m1v1+ m2v2
110*8+ 110*-10= 110*-10 + 110* v2
v2= 8 m/sec
Density <em>ρ</em> is mass <em>m</em> per unit volume <em>v</em>, or
<em>ρ</em> = <em>m</em> / <em>v</em>
Solving for <em>v</em> gives
<em>v</em> = <em>m</em> / <em>ρ</em>
So the given object has a volume of
<em>v</em> = (130 g) / (65 g/cm³) = 2 cm³
Answer is on the image with the explanation. I hope that might help you with the answers
If you're holding the apple at your waist, lift it to your mouth.
Potential energy relative to any level is proportional to its height
above that level. Increase that height, and you've increased the
potential energy.
Since energy is conserved ... it never magically appears or
disappears ... you need to tell where that extra energy for the
apple came from.
It's exactly the work you did ... the force of your muscles acting
through the distance you raised the apple ... that became the
additional potential energy that the apple gained.
