A certain lead-acid storage battery has a mass of 30 kg. starting from a fully charged state, it can supply 5 a for 24 hours wit
h a terminal voltage of 12 v before it is totally discharged.
a. if the energy stored in the fully charged battery is used to lift the battery with 100-percent efficiency, what height is attained? assume that the acceleration due to gravity is 9.8 m/s2 and is constant with height. b if the stored energy is used to accelerate the battery with 100 percent efficiency, what velocity is attained?
c. gasoline contains about 4.5 x 107 j/kg. compare this with the energy content per unit mass for the fully charged battery.
a. if the energy stored in the fully charged battery is used to lift the battery with 100-percent efficiency, what height is attained? assume that the acceleration due to gravity is 9.8 m/s2 and is constant with height. b if the stored energy is used to accelerate the battery with 100 percent efficiency, what velocity is attained?
c. gasoline contains about 4.5 x 107 j/kg. compare this with the energy content per unit mass for the fully charged battery.
1 answer:
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Mass of the block = 1.4 kg
Weight of the block = mg = 1.4 × 9.8 = 13.72 N
Normal force from the surface (N) = 13.72 N
Acceleration = 1.25 m/s^2
Let the coefficient of kinetic friction be μ
Friction force = μN
F(net) = ma
μmg = ma
μg = a
μ =
μ =
μ = 0.1275
Hence, the coefficient of kinetic friction is: μ = 0.1275
Answer:
a) F₃₁ = 63.0 μN
b) F₃₂ = - 14.0 μN
c) q₂ = - 5.0 nC
Explanation:
a)
- Assuming that the three charges can be taken as point charges, the forces between them must obey Coulomb's Law, and can be found independent each other, applying the superposition principle.
- So, we can find the force that q₁ exerts along the x-axis on q₃, as follows:
b)
- Since total force exerted by q₁ and q₂ on q₃ is 49.0 μN, we can find the force exerted only by q₂ (which is along the x-axis only too) just by difference, as follows:
c)
- Finally, in order to find the value of q₂, as we know the value and sign of F₃₂, we can apply again the Coulomb's Law, solving for q₂, as follows: