What symbol is used when representing momentum in equations?

Superman is flying 54.5 m/s when he sees

Nady [450]

348.34 m/s. When Superman reaches the train, his final velocity will be 348.34 m/s.

To solve this problem, we are going to use the kinematics equations for constant aceleration. The key for this problem are the equations $d=v_{0} t+\frac{at^{2} }{2}$ and $v_{f} =v_{0} +at$ where $d$ is distance, $v_{0}$ is the initial velocity, $v_{f}$ is the final velocity, $t$ is time, and $a$ is aceleration.

Superman's initial velocity is $v_{0}=54.5\frac{m}{s}$ , and he will have to cover a distance d = 850m in a time t = 4.22s. Since we know $d$ , $v_{0}$ and $t$ , we have to find the aceleration $a$ in order to find $v_{f}$ .

From the equation $d=v_{0} t+\frac{at^{2} }{2}$ we have to clear $a$ , getting the equation as follows: $a=\frac{2(d-v_{0}t) }{t^{2} }$ .

Substituting the values:

$a=\frac{2(850m-54.5\frac{m}{s}.4.22s) }{(4.22s)^{2}}=69.63\frac{m}{s^{2}}$

To find $v_{f}$ we use the equation $v_{f} =v_{0} +at$ .

Substituting the values:

$v_{f} =54.5\frac{m}{s} +(69.63\frac{m}{s^{2}}.4.22s)=348.34\frac{m}{s}$

5 0

3 years ago

At an altitude of 5000 m the rocket's acceleration has increased to 6.9 m/s2 . What mass of fuel has it burned?

sergey [27]

1) Initial upward acceleration: $6.0 m/s^2$

2) Mass of burned fuel: $0.10\cdot 10^4 kg$

Explanation:

1)

There are two forces acting on the rocket at the beginning:

- The force of gravity, of magnitude $F_g = mg$ , in the downward direction, where

$m=1.9\cdot 10^4 kg$ is the rocket's mass

$g=9.8 m/s^2$ is the acceleration of gravity

- The thrust of the motor, T, in the upward direction, of magnitude

$T=3.0\cdot 10^5 N$

According to Newton's second law of motion, the net force on the rocket must be equal to the product between its mass and its acceleration, so we can write:

$T-mg=ma$ (1)

where a is the acceleration of the rocket.

Solving for a, we find the initial acceleration:

$a=\frac{T-mg}{m}=\frac{3.0\cdot 10^5-(1.9\cdot 10^4)(9.8)}{1.9\cdot 10^4}=6.0 m/s^2$

2)

When the rocket reaches an altitude of 5000 m, its acceleration has increased to

$a'=6.9 m/s^2$

The reason for this increase is that the mass of the rocket has decreased, because the rocket has burned some fuel.

We can therefore rewrite eq.(1) as

$T-m'g=m'a'$

where

$m'$ is the new mass of the rocket

Re-arranging the equation and solving for m', we find

$m'=\frac{T}{g+a}=\frac{3.0\cdot 10^5}{9.8+6.9}=1.8\cdot 10^4 kg$

And since the initial mass of the rocket was

$m=1.9 \cdot 10^4 kg$

This means that the mass of fuel burned is

$\Delta m = m-m'=1.9\cdot 10^4 - 1.80\cdot 10^4 = 0.10\cdot 10^4 kg$

3 0

3 years ago

a rocket engine can accelerate a rocket launched from rest vertically up with an acceleration of 22.9 m/s2. however, after 50.0

xxTIMURxx [149]

The acceleration of a rocket engine is given here, and after 50 seconds of flight, the engine fails, and we must determine the altitude of the rocket at the time the engine fails. Because the rocket starts from rest, the time taken is 50 seconds, the initial velocity is zero, and the acceleration is 22.9 meters per second square. So we use the kinamatics equation s equal to v. I t plus half 8 square. There is no acceleration at the start. 22.9 and t is 50 seconds, so displacement 2.86 times 10 to the power 4 is met. This is the rocket's displacement in 50 seconds, so this is the rocket's altitude when the engine fails.

<h3>What exactly is accelerate?</h3>

In mechanics, acceleration is defined as the rate of change of an object's velocity with respect to time. Vector quantities are accelerations. The orientation of an object's acceleration is determined by the orientation of its net force.

In his second law of motion, Sir Isaac Newton (1642-1727) defined acceleration as the ratio of a force acting on an object to its mass: a = f/m.

Accelerate is a verb that means to speed up. When you press the gas pedal, the car accelerates. If you know someone who works at the consulate, you can speed up the process.

Acceleration is the rate at which velocity changes over time, both in terms of speed and direction. A point or object moving in a straight line is accelerated if it accelerates or decelerates.

Even if the speed is constant, motion on a circle is accelerated because the direction is constantly changing. Both effects contribute to acceleration in all other types of motion.

Hence, There is no acceleration at the start. 22. This is the rocket's displacement in 50 seconds, so this is the rocket's altitude when the engine fails.

To know more about Accelerate refer to:

brainly.com/question/460763

#SPJ4

3 0

1 year ago

Lori’s family is on a road trip. They split their drive into the five legs listed in the table. Find the average velocity for ea

NARA [144]

It's not possible to answer the question exactly the way it's written.
That's because we don't know anything about the direction they
drive at any time during the trip.

You see, "velocity" is not just a word that you use for 'speed' when
you want to sound smart and technical, like this question is doing.
"Velocity" is a quantity that's made up of speed AND THE DIRECTION
of the motion. If you don't know the direction of the motion, then you
CAN'T tell the velocity, only the speed.

Here are the average speeds that Lori's family drove on each leg
of their trip:

Speed = (distance covered) / (time to cover the distance) .

Leg-A:
Speed = 15km/10min = 1.5 km/min

Leg-B:
Speed = 20km/15min = (1 and 1/3) km/min

Leg-C
Speed = 24km/12min = 2 km/min

Leg-D:
Speed = 36km/9min = 4 km/min

Leg-E:
Speed = 14km/14min = 1 km/min

From lowest speed to highest speed, they line up like this:

[Leg-E] ==> [Leg-B] ==> [Leg-A] ==> [Leg-C] ==> [Leg-D]
1.0 . . . . . . . . 1.3 . . . . . . . 1.5 . . . . . . . 2.0 . . . . . . . 4.0 . . . . km/minute

Whoever drove Leg-D should have been roundly chastised
and then abandoned by the rest of the family.  36 km in 9 minutes
(4 km per minute) is just about 149 miles per hour !

4 0

3 years ago

Read 2 more answers

How do convection currents influence plate tectonics

jarptica [38.1K]

Answer and Explanation:

Convection happens when particles with a great deal of warmth vitality in a fluid or gas move and replace particles with less warmth vitality.

Lighter (less thick), warm material ascents while heavier (progressively thick) cool material sinks. It is this development that makes course examples known as convection flows in the environment, in water, and in the mantle of Earth.

Huge amount of pressure and heat inside the earth causes the hot magma to stream in convection ebbs and flows. These flows cause the development of the structural plates that make up the world's outside.

Plates at our planet's surface move in view of the extreme warmth in the Earth's center that causes liquid shake in the mantle layer to move.
It moves in an example considered a convection cell that structures when warm material ascents, cools, and in the long run sink down. As the chilled material sinks off, it is warmed and rises once more.

5 0

3 years ago