Answer:
If the cosmos emerged from the Big Bang with sufficiently high density, then it contains enough matter to halt its own expansion and the recession of galaxies will stop. Red shifts will turn to blue shifts as the universe begins collapsing inward and stars and planets and galaxies will collide with increasing frequency and violence as space diminishes. The entire universe will shrink towards a super dense, super hot singularity, much like the one from which it originated, the "big crunch".
Gravity of a low density universe will be too weak to half the present expansion. The universe will expand forever, the galaxies continually receding, their radiation steadily weakening with increasing distance.
In time, we will see no galaxies in the sky beyond the Local Group. Eventually, the Local Group will peter out as their fuel supply is consumed. A "cold death" will happen whereby all radiation, matter, and life are eventually destined to freeze. This would take about a trillion years to happen.
The universe can expand forever, in which case we die a cold death in which all activity gradually fades away, or the expansion can stop and the universe will recollapse to a fiery Big Crunch.
Distance = rate * time
d = (20.0 mph)(0.500 hr) + (40.0 mph)(1.00 hr) + (30.0 mph)(0.500 hr) + (50.0 mph)(2.00 hr)
d = 10.0 miles + 40.0 miles + 15.0 miles + 100. miles
d = 165 miles
Answer:
Explanation:
Time to cover first 100 km = 1 hour.
time remaining = 3.15 - 1 = 2.15 hour .
Time to cover next 42 km = 1 hour .
Time remaining = 2.15-1 = 1.15 hour.
Distance to be covered = 310 - 142
= 168 km
least speed needed = distance remaining / time remaining
= 168 / 1.15
= 146.08 km / h .
The formula for finding potential energy is: f= m*g*h. where "m" is mass of the object in question. "g" is the gravitational acceleration."h" is height above the ground. So, if we put in the values:
joules
A is the answer. If you half the distance the force will quadruple due to gravitational force obeying the inverse square law of 1/r^2