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3 years ago

A 4.0 kg model rocket is launched, shooting 50.0 g of burned fuel from its exhaust at

Physics

1 answer:

Anettt [7]3 years ago

3 0

The velocity of the rocket is 7.8 m/s

Explanation:

We can solve the problem by using the law of conservation of momentum: in fact, in absence of external forces, the total momentum of the rocket+fuel system must be conserved.

Before the launch, the total momentum of the system is zero, since the rocket and the fuel are at rest:

$p=0$

After the launch, the total momentum is

$p=MV+mv$

where

M = 4.0 kg is the mass of the rocket

V is the velocity of the rocket

m = 50.0 g = 0.050 kg is the mass of the fuel ejected

v = -625 m/s is the velocity of the fuel (taking "backward" as negative direction)

Since the total momentum is conserved, we have

$0=MV+mv$

So we can solve the equation to find V, the velocity of the rocket:

$V=-\frac{mv}{M}=-\frac{(0.050)(625)}{4.0}=+7.8 m/s$

And the positive sign means the rocket moves forward.

Learn more about momentum:

brainly.com/question/7973509

brainly.com/question/6573742

brainly.com/question/2370982

brainly.com/question/9484203

#LearnwithBrainly

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If the electron has half the speed needed to reach the negative plate, it will turn around and go towards the positive plate. Wh

In-s [12.5K]

Answer:

v = -v₀ / 2

Explanation:

For this exercise let's use kinematics relations.

Let's use the initial conditions to find the acceleration of the electron

v² = v₀² - 2a y

when the initial velocity is vo it reaches just the negative plate so v = 0

a = v₀² / 2y

now they tell us that the initial velocity is half

v’² = v₀’² - 2 a y’

v₀ ’= v₀ / 2

at the point where turn v = 0

0 = v₀² /4 - 2 a y '

v₀² /4 = 2 (v₀² / 2y) y’

y = 4 y'

y ’= y / 4

We can see that when the velocity is half, advance only ¼ of the distance between the plates, now let's calculate the velocity if it leaves this position with zero velocity.

v² = v₀² -2a y’

v² = 0 - 2 (v₀² / 2y) y / 4

v² = -v₀² / 4

v = -v₀ / 2

We can see that as the system has no friction, the arrival speed is the same as the exit speed, but with the opposite direction.

7 0

3 years ago

What living things began to increase in numbers following this mass extinction?

RoseWind [281]

pigsExplanation: population

8 0

3 years ago

What is the wavelength of a 10 Hz wave that travels with a speed of 5 m/s?

garik1379 [7]

B

V= f x lambda
V= 5m/s
F = 10hz
Lambda = ?
5 = 10 x lamba
5 /10 = lambda
Wavelength =0.5

8 0

2 years ago

An elevator motor provides 45.0 kW of power while lifting an elevator 35.0 m. If the elevator contains seven passengers each wit

mylen [45]

Find how much work ∆W is done by the motor in lifting the elevator:

P = ∆W / ∆t

where

• P = 45.0 kW = power provided by the motor

• ∆W = work done

• ∆t = 20.0 s = duration of time

Solve for ∆W :

∆W = P ∆t = (45.0 kW) (20.0 s) = 900 kJ

In other words, it requires 900 kJ of energy to lift the elevator and its passengers. The combined mass of the system is M = (m + 490.0) kg, where m is the mass of the elevator alone. Then

∆W = M g h

where

• g = 9.80 m/s² = acceleration due to gravity

• h = 35.0 m = distance covered by the elevator

Solve for M, then for m :

M = ∆W / (g h) = (900 kJ) / ((9.80 m/s²) (35.0 m)) ≈ 2623.91 kg

m = M - 490.0 kg ≈ 2133.91 kg ≈ 2130 kg

4 0

3 years ago

Adding or removing thermal energy to or from a substance does not always cause its temperature

julia-pushkina [17]

Change in thermal energy not always cause it's temperature change. It is the situation when water reaches either at 0 C or 100 C then thermal energy doesn't cause change in temperature instead it changes the state of matter.

In short, Your Answer would be "True"

Hope this helps!

6 0

3 years ago

Read 2 more answers