Answer:
Polished surfaces reduce heat loss
B, we can use a power drill for an example, the motars are used by electricity (electrical energy) and used to screw in wood (mechanical energy)
Here is the answer to the given question above. Based on the Raisin Cake Analogy, the two properties of distant galaxies that astronomers have to measure to show<span> that we live in an expanding universe are DISTANCE and SPEED. Hope this answers your question. Have a great day!</span>
Answer:
Explanation:
ignoring air resistance, the kinetic energy at water impact will equal the potential energy converted
½mv² = mgh
v = √(2gh)
v = √(2(9.81)2.1) = 6.4188... m/s
after impact, an impulse will result in a change of momentum.
There is a downward impulse due to gravity equal to the weight of the stone and an upward average force due to water resistance and buoyancy force.
FΔt = mΔv
(F - mg)Δt = m(vf - vi)
(F - mg) = m(vf - vi)/Δt
F = m(vf - vi)/Δt + mg
F = m((vf - vi)/Δt + g)
F = 1.05(((½(-6.4188) - -6.4188)/ 1.83) + 9.81)
F = 12.14198...
F = 12.1 N
