Answer:I think its the first one
Explanation:
Answer and Explanation:
Before turning a hot plate on, one should consider these points:
- Check for the leads and ensure they does not trail in liquid.
- The cable should be checked for any exposed wire before turning on in order to prevent any shock.
- Any oil residue should be wiped off of the hot plate to ensure its longevity.
- It should be placed in a stable place in order to ensure safety against any hazard.
- Thus all the above mentioned points are correct to ensure safety.
The statement that is true is that positively charged objects attract negatively charged objects. This is due to a law that states 'like forces attract while unlike forces repel. This same concept applies to magnetism. If you put two similar poles together, for example; if you place two south poles together. You feel a separating force between the two poles. But if you place two opposite poles together they attract each other. Hope i helped. <span />
<span>A person expended 500 newtons to move a full wheelbarrow 30 meters how much work was done?
</span>In physics, a force is said to do work<span> if, when acting, there is a displacement of the point of application in the direction of the force. The work done would be calculated as follows:
</span>
W = F x d = 500 N (30 m) = 15000 J or 15 kJ
Answer:
Explanation:
F = 2.12 x 10⁻²⁶ / x²
Work done by electric field of nucleus
W = ∫ Fdx
= ∫2.12 x 10⁻²⁶ / x² dx
= 2.12 x 10⁻²⁶ ( - 1 / x )
= - 2.12 x 10⁻²⁶ ( 1/5 - 1 / 8 x 10⁻¹⁰ )
= - .265 x 10⁻¹⁶ J
1/ 2 x mv² = .5 x 1.67 x 10⁻²⁷ x 9 x 10¹⁰ - .265 x 10⁻¹⁶
= 7.515 x 10⁻¹⁷ - .265 x 10⁻¹⁶
=( .7515 - .265 )x 10⁻¹⁶
= .4865 x 10⁻¹⁶
.5 x 1.67 x 10⁻²⁷ x v² = .4865 x 10⁻¹⁶
v² = .5826 x 10¹¹
v² = 5.826 x 10¹⁰
v = 2.41 x 10⁵ m /s
b )
Let r be the closest distance
Potential at this point
2.12 x 10⁻²⁶ ( 1 / r )
Kinetic energy
= 0
Total energy = 2.12 x 10⁻²⁶ ( 1 / r )
Total energy at 5 m
= .5 x 1.67 x 10⁻²⁷ x 9 x 10¹⁰ + 0 ( potential energy at 5 m will be negligible as compared with that near the center )
= 7.515 x 10⁻¹⁷ J
So ,
2.12 x 10⁻²⁶ ( 1 / r ) = 7.515 x 10⁻¹⁷
r = 2.12 x 10⁻²⁶ / 7.515 x 10⁻¹⁷
= .282 x 10⁻⁹
= 2.82 x 10⁻¹⁰ m
c ) As electric field is conservative , no dissipation of energy takes place . Hence its speed at 5m on returning back to this point will be same as
3.00 x 10⁵ m /s
