Answer: 1,600 seconds
Explanation:
31,360/9.8 = 3,200.
Then divide 3,200/2 = 1,600
Kinetic energy is the energy of the motion.
This is because the kinetic energy can be calculated by using the formula,
K.E.=1/2 mv^2
where, v is the velocity of moving body i.e. the body is in motion.
IF there is no air resistance, then he could drop a feather, a piece
of Kleenex, a school bus, and a battleship. If he dropped them all
at the same time from the same height, they would all hit the ground
at the same time.
Contact and non contact forces are big factors to consider
in designing of different modes of transportation because this factors are
resistances for the mode of transportation. These contact and non- contact
forces should be minimized in order for the energy requirement to be also
minimum. But not the extent of risking the safety, for example a non contact
force is the wieght, the should be optimum, safety of the design should not be
compromised just to reduce weight, just like by removing essential parts,
support just to remove weight is not good.
When we look at the moon from the Earth, we always see the same light spots, dark spots, and shapes. It never changes. There could be two possible reasons for this:
-- The moon is a flat disk with some markings on it, and one side of it always faces the Earth.
-- The moon is a round ball with some markings on it, and one side of it always faces the Earth.
Either way, since the same side always faces the Earth, the only way that can happen is if the moon's revolution around the Earth and rotation on its axis both take EXACTLY the same length of time.
Even if they were only one second different, then we would see the moon's whole surface over a long period of time. But we don't. So the moon's rotation and revolution must be EXACTLY locked to the same period of time.
