All categories

3 years ago

the public is not yet able to purchase hydrogen fuel cell powered cars because engineers have to determine

Physics

1 answer:

grigory [225]3 years ago

3 0

Answer: This would more a practical feedback than scientific.

Explanation: Despite of the protocols and processes scientists need to develop in order to stablish a new source of energy or daily life option, logistic issues are one of the most important things on the "to do list".

Would it be very expensive to acquire this kind of fuel? Is it efficient? Is it dangerous to human life or the environment? What about the negative reactions this brand new fuel could have in society?.

You might be interested in

A plane drops a rubber raft to the survivors of a shipwreck. The plane is flying at a height of 1960 m and with a speed of 109 m

Korolek [52]

In this case the rubber raft has horizontal and vertical motion.

Considering vertical motion first.

We have displacement $s = ut +\frac{1}{2}at^2$ , u = Initial velocity, t = time taken, a = acceleration.

In vertical motion

s = 1960 m, u = 0 m/s, a = 9.81 $m/s^2$

$1960 = 0*t+\frac{1}{2} *9.81*t^2\\ \\ t = 20 seconds$

So raft will take 20 seconds to reach ground.

Now considering horizontal motion of raft

u = 109 m/s, t = 20 s, a = 0 $m/s^2$

So $s = 109*20+\frac{1}{2} *0*20^2 = 2180 m$

So shipwreck was 2180 meter far away from the plane when the raft was dropped.

8 0

3 years ago

On February 15, 2013, a superbolide meteor (brighter than the Sun) entered Earth's atmosphere over Chelyabinsk, Russia, and expl

fredd [130]

Answer:

156.67 m/s

0.45676 times the speed of sound

Explanation:

Distance from the ground = 23.5 km = 23500 m

Time taken by the blast waves to reach the ground = $2\ minutes\ 30\ seconds=2\times 60+30=150\ s$

Spedd of the wave would be

$Speed=\dfrac{Distance}{Time}\\\Rightarrow v_b=\dfrac{23500}{150}\\\Rightarrow v-b=156.67\ m/s$

The velocity of the blast wave is 156.67 m/s

v = Velocity of sound = 343 m/s

$\dfrac{v_b}{v}=\dfrac{156.67}{343}\\\Rightarrow v_b=v\dfrac{156.67}{343}\\\Rightarrow v_b=0.45676v$

The blast wave is 0.45676 times the speed of sound

7 0

3 years ago

Astronauts are trained for take-off in a high-speed centrifuge of 4.7 m radius that spins in the horizontal plane.

Leokris [45]

Answer:

a) $1.94 \frac{rad}{s}$

b) $9.12\frac{m}{s}$

c) Towards the center of the centrifuge

Explanation:

Becuse the centrifuge rotates in circular motion, there's an angular acceleration tha simulates high gravity accelerations

$a_{rad}=\omega r^{2}$

with r the radius and ω the amgular velocity, in or case $a_rad=3.5g$ so:

$3.5g=\omega r^{2}$ and g=9.8 $\frac{m}{s^{2}}$

solving for ω:

$\omega=\frac{3.5g}{r^2}=\frac{3.5*9.8}{4.2^2}$

$\omega = 1.94 \frac{rad}{s}$

b) Linear speed (v) and angular speed are related by:

$v=\omega r =(1.94)(4.7)$

$v= 9.12\frac{m}{s}$

c) The apparent weigth is pointing towards the center of the circle, becuse angular acceleration is pointing in that direction.

8 0

3 years ago

Compare and contrast the theories about the origin of the universe

Vaselesa [24]

Answer:

The best-supported theory of our universe's origin centers on an event known as the big bang. This theory was born of the observation that other galaxies are moving away from our own at great speed in all directions, as if they had all been propelled by an ancient explosive force.

Explanation:

hope this helps tho i don't quite know what you mean

7 0

3 years ago

Elements produce their spectrum when their electrons _____.

Aleonysh [2.5K]

The correct answer is the third one: move toward the ground state. Remember please that Elements produce their spectrum when their electrons move toward the ground state. Hope this is very useful

5 0

3 years ago