Which is the best example of forces acting in the same direction? a boy lifting his chest off the ground during a pushup. two football players pushing a tackling sled. a person pulling out a garden hose from its reel.
Answer:
Explanation:
Potential energy at the top of the slide
PE = mgh = 49(9.8)(3) = 1,440.6 J
Energy converted to work of friction
W = Fd = 35(10) = 350 J
Converted potential that becomes kinetic energy
1440.6 - 350 = 1090.6 J
KE = ½mv²
v = 
v = 
v = 6.671902...
v = 6.7 m/s
Answer:
The new Coulomb force is q₁q₂/9πε₀r²
Explanation
The coulomb force between the two charges q₁ and q₂ at a distance r in air is given by F = q₁q₂/4πε₀r².
Now, let us assume the material of dielectric constant κ = 9 is placed between them on the side of the q₁ charge. The value of its effective charge is now q₃ = q₁/κ at a distance of d = r/2 from the q₂ charge.
Since we have air between q₂ and q₃, the coulomb force between them is
F' = q₂q₃/4πε₀d²
= q₂(q₁/κ)/4πε₀(r/2)²
= 4q₂q₁/κ4πε₀r²
= 4/κ(q₂q₁/4πε₀r²)
= 4/9 × (q₂q₁/4πε₀r²)
= q₁q₂/9πε₀r²
So, the new Coulomb force is q₁q₂/9πε₀r²
Answer:
It is directed inward, toward the center of a circle.
(a). If the temperature of a substance is increased the density of it will also increased. The temperature is directly proportional to the density because the molecular activity of the substance will be affected by the temperature
(b).The mass of the substance doesn't at all. Because the amount of matter inside the substance cannot be affected by the temperature except that its water
