Answer:
a) t = 4.14 s
b) Speed with which it hits the ground = 40.58 m/s
Explanation:
Using the equations of motion,
g = 9.8 m/s², y = H = 84 m,
Initial velocity, u = 0 m/s,
final velocity, v = ?
Total Time of fall, t = ?
a) y = ut + gt²/2
84 = 0 + 9.8t²/2
4.9t² = 84
t² = 84/4.9
t = 4.14 s
b) v = u + gt
v = 0 + (9.8 × 4.14)
v = 40.58 m/s
Answer:
Einstein's equivalence principle says that __________.
the effects of gravity are exactly equivalent to the effects of acceleration
Explanation:
The equivalence principle is one of the fundamental laws of physics, as enunciated by Einstein. It categorically states that the gravitational and inertial forces are of a similar nature. In physics, a gravitational acceleration is the acceleration of an object in a free fall within a space. The importance of Einstein's Equivalence Principle is explained by his theory of general relativity. This theory states that mass is the same, whether inertial or gravitational.
A galaxy is a large system of stars, remnants of dead stars, dust,
interstellar gas, and dark matter, all related to each other by gravity.
Within the part of the universe that we can observe, it's estimated that
there may be as many as two trillion galaxies !
Galaxies come in all sizes. Tiny shrimp galaxies hold no more than
a few billion stars. Really big galaxies may hold 100 trillion stars. ( ! ! )
The galaxy we live in (the "Milky Way") is somewhere in the middle.
It's very hard to estimate the number of stars in it, because we can't
get outside of it and look it over. Estimates of the number of stars in
our galaxy range from 100 billion to 400 billion stars. ( ! ! ! )
The answer is <span>higher than.
</span><span>A sound-producing object is moving toward an observer. The sound the observer hears will have a frequency higher than that actually being produced by the object.
Why?
</span>As the source of the waves is moving toward the observer, each of the successive wave crest<span> is emitted from a position closer to the observer than the previous wave.
Thus each wave takes slightly less time to reach the observer than the previous wave. So, the time between the arrival of successive wave crests at the observer is reduced, increasing the frequency. </span>
