Answer:
(E)56.0 m/s
Explanation:
Height =h=-160 m
Because the wallet moving in downward direction
Time=t=7 s
Final speed of wallet=v=0
We have to find the speed of helicopter ascending at the moment when the passenger let go of the wallet.

Where 
Substitute the values



Option (E) is true
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
The answer is true. All the galaxies in the universe follow
the law of gravity.
<span>Based from the book, It's about Time: the Illusion of
Einstein’s Time Dilation Explained, </span>
Einstein had explained that all the heavenly bodies in the
universe follow the same scientific laws that are similar to our solar system. The
stars and planets are held by the principles of inertia and gravity
Power = Work Done / Time taken
Where Work Done is Joules, and Time is in Seconds, Power is in Watts
= 2400 J / 6 seconds
= 400 Watts
The power output is 400 Watts.