Does the coefficient of kinetic friction depend on speed?

How did the ideas of einstein and freud contribute to a sense of uncertainty?

Ipatiy [6.2K]

Einstein's Theory of Relativity was a theory which carried about hesitation in Newton's gravity which was measured as an important part of science. Which brings one to query what we detect as being factual.
Freud's thoughts about the subliminal questions one's own mind to what we have faith in. Is a dream just a dream, or is it your subliminal trying to tell you a little? It brought about a feeling of being ignorant of what is going on in your own mind.
These and maybe other bring persons to doubt about the world about them and within themselves.

6 0

3 years ago

The portion of a sound wave with higher-than-normal pressure is called a(n)________

Leokris [45]

Answer:

Condensation

Explanation:

Increased pressure is called condensation or compressions because they are regions of high air pressure whilst rarefractions are low air pressure.

4 0

3 years ago

Tourists covered 255 km for a 4-hour ride by car and a 7-hour ride by train. what is the speed of the train, if it is 5 km/h gre

LekaFEV [45]

The distance covered by car is equal to (assuming it is moving by uniform motion) the product between the car's speed and the time of the car ride, 4 h:
$S_c = v_c t_c$
where
$v_c$ is the car's speed
$t_c = 4 h$ is the duration of the car ride

Similarly, the distance covered by train is equal to the product between the train's speed and the duration of the train ride, 7 h:
$S_t = v_t t_t$

The total distance covered is S=255 km, which is the sum of the distances covered by car and train:
$S=255 km = S_c + S_t$
which becomes
$255 = 4 v_c + 7 v_t$ (1)
we also know that the train speed is 5 km/h greater than the car's speed:
$v_t = 5 + v_c$ (2)

If we put (2) into (1), we find
$255 = 4v_c + 7(5+v_c)$
and if we solve it, we find
$v_c = 20 km/h$
$v_t = 25 km/h$

So, the car speed is 20 km/h and the train speed is 25 km/h.

4 0

4 years ago

The primary difference between mechanical waves and electromagnetic waves is that mechanical waves need a _________ to travel th

morpeh [17]

Answer:

Medium

Explanation:

Electromagnetic waves (light, electricity) can travel through space, which has no medium (air), while mechanical waves cannot. The main medium for mechanical waves is air, and without the medium, the wave cannot travel. This is why you cannot hear sound in space.

The roaring spacecraft in Star Wars is false.

4 0

3 years ago

A trick shot archer shoots an arrow with a velocity of 30.0 m/s at an angle of 20.0 degrees with respect to the horizontal. An a

svlad2 [7]

Answer:

$u'=10.259\ m.s^{-1}$ is the initial velocity of tossing the apple.