Answer:
D
Explanation:
Water in itself is a bad conductor of electricity. Any compound that dissociates in water into ions and charged molecules, will increase conductivity of water. In this case ionic compounds weak basis and acids will put in free ions into the water. The ions can pass electricity because they are attracted to respective poles of electricity depending on their charges. In water, these ions are free moving unlike when they are immobilized in their lattice in solid form.
Organic compounds are mainly made of covalent bonds (around carbon) hence do not dissociate in water.
'N' is labelled 'runoff'. That's when the water is down. Streets are wet, worms come out of the ground, and water flows down the street to the sewer.
Here As we can see the figure that the end of the rope is pulled by some force F
Now as we can see that Piano is connected by a pulley which is passing over the pulley so effectively net force on the piano upwards will be 2F as it is connected by 2 ropes by the pulley
Now for constant velocity of the piano we will say

since velocity is constant so acceleration must be ZERO
so here we have

as we know here that
mg = 1000 N
so we will have


so here force must be 500 N
Answer:
A) F=-20.16×10⁹N
B) if the distance doubles, force is 4 times smaller.
Explanation:
q1=-28C
q2=5mC=0.005C
d=25cm=0.25m
Electrostatic force between charges: F=k×q1×q2/d², where k is a coefficient that has the value k=9 × 10⁹ N⋅m²⋅C^(-2) for air.
Thus:
F=9×10⁹×(-28)×0.005/0.25²
F=-20.16×10⁹N
The minus sign indicates attraction.
If distance doubles, d1=2×d, then we have 4d² at the denominator and the force is 4 times smaller.
Answer:
A. Velocity
Explanation:
Velocity is vector quantity thus has both magnitude and direction. It describes not only the speed but also the direction. Speed is scalar quantity so describes only speed but not direction. Energy has nothing to do with speed, acceleration describes change in velocity in a direction over time