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3 years ago

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Nikolas had an idea that he could use the compressed carbon dioxide in a fire extinguisher to propel him on his skateboard. Niko

las, the fire extinguisher, and the skateboard have a combined mass of 50 kg. What force would the fire extinguisher have to produce to propel Nikolas if he wanted to accelerate at a rate of 1.2 m/s2? Round your answer to the nearest whole newton. 60 N Which of Newton’s laws did Nikolas have to use to calculate this force?

2 answers:

pashok25 [27]3 years ago

5 1

Answer:

The answer is the Second Force

Explanation:

Harman [31]3 years ago

3 1

second force boiiiiiiiiiii

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A potter's wheel has the shape of a solid uniform disk of mass 7 kg and radius 0.65 m. It spins about an axis perpendicular to t

ozzi

Answer:

1.832 kgm^2

Explanation:

mass of potter's wheel, M = 7 kg

radius of wheel, R = 0.65 m

mass of clay, m = 2.1 kg

distance of clay from centre, r = 0.41 m

Moment of inertia = Moment of inertia of disc + moment f inertia of the clay

I = 1/2 MR^2 + mr^2

I = 0.5 x 7 x 0.65 x 0.65 + 2.1 x 0.41 x 0.41

I = 1.47875 + 0.353

I = 1.832 kgm^2

Thus, the moment of inertia is 1.832 kgm^2.

5 0

4 years ago

Steam enters an adiabatic turbine steadily at 7 MPa, 5008C, and 45 m/s, and leaves at 100 kPa and 75 m/s. If the power output of

marusya05 [52]

Answer:

a) $\dot m = 6.878\,\frac{kg}{s}$ , b) $T = 104.3^{\textdegree}C$ , c) $\dot S_{gen} = 11.8\,\frac{kW}{K}$

Explanation:

a) The turbine is modelled by means of the First Principle of Thermodynamics. Changes in kinetic and potential energy are negligible.

$-\dot W_{out} + \dot m \cdot (h_{in}-h_{out}) = 0$

The mass flow rate is:

$\dot m = \frac{\dot W_{out}}{h_{in}-h_{out}}$

According to property water tables, specific enthalpies and entropies are:

State 1 - Superheated steam

$P = 7000\,kPa$

$T = 500^{\textdegree}C$

$h = 3411.4\,\frac{kJ}{kg}$

$s = 6.8000\,\frac{kJ}{kg\cdot K}$

State 2s - Liquid-Vapor Mixture

$P = 100\,kPa$

$h = 2467.32\,\frac{kJ}{kg}$

$s = 6.8000\,\frac{kJ}{kg\cdot K}$

$x = 0.908$

The isentropic efficiency is given by the following expression:

$\eta_{s} = \frac{h_{1}-h_{2}}{h_{1}-h_{2s}}$

The real specific enthalpy at outlet is:

$h_{2} = h_{1} - \eta_{s}\cdot (h_{1}-h_{2s})$

$h_{2} = 3411.4\,\frac{kJ}{kg} - 0.77\cdot (3411.4\,\frac{kJ}{kg} - 2467.32\,\frac{kJ}{kg} )$

$h_{2} = 2684.46\,\frac{kJ}{kg}$

State 2 - Superheated Vapor

$P = 100\,kPa$

$T = 104.3^{\textdegree}C$

$h = 2684.46\,\frac{kJ}{kg}$

$s = 7.3829\,\frac{kJ}{kg\cdot K}$

The mass flow rate is:

$\dot m = \frac{5000\,kW}{3411.4\,\frac{kJ}{kg} -2684.46\,\frac{kJ}{kg}}$

$\dot m = 6.878\,\frac{kg}{s}$

b) The temperature at the turbine exit is:

$T = 104.3^{\textdegree}C$

c) The rate of entropy generation is determined by means of the Second Law of Thermodynamics:

$\dot m \cdot (s_{in}-s_{out}) + \dot S_{gen} = 0$

$\dot S_{gen}=\dot m \cdot (s_{out}-s_{in})$

$\dot S_{gen} = (6.878\,\frac{kg}{s})\cdot (7.3829\,\frac{kJ}{kg\cdot K} - 6.8000\,\frac{kJ}{kg\cdot K} )$

$\dot S_{gen} = 11.8\,\frac{kW}{K}$

4 0

4 years ago

An aerobatic airplane pilot experiences weightlessness as she passes over the top of a loop the loop maneuver. The acceleration

Natali5045456 [20]

The radius of the loop is 18.9 km

Explanation:

When the airplane is at the top of the loop, the pilot experiences two forces:

The force of gravity, acting downward, of magnitude $mg$
The normal reaction exerted by the seat on the pilot, also acting downward, N

Since the plane is moving in a circular motion, the net force on the pilot must be equal to the centripetal force, therefore we can write:

$mg+N = m\frac{v^2}{r}$

where

m is the mass of the pilot

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

N is the normal reaction

v = 430 m/s is the speed of the plane

r is the radius of the loop

Here we are told that the pilot feel weightless at the top of the loop: this means that the normal reaction is zero,

N = 0

Therefore the equation becomes

$mg=\frac{mv^2}{r}$

And so we can find the radius of the loop:

$r=\frac{v^2}{g}=\frac{430^2}{9.8}=18.9 \cdot 10^3 m = 18.9 km$

Learn more about circular motion:

brainly.com/question/2562955

brainly.com/question/6372960

#LearnwithBrainly

8 0

3 years ago

When making a budget, you should prioritize ___________ before "__________." A. Needs/wants B. Wants/needs C. Electricity/Water

cestrela7 [59]

Answer:

Needs, Wants

Explanation:

Needs are necessary, wants are not

7 0

4 years ago

What is the best description of the destructive interference of light?

Lelechka [254]

Answer:

B. Two waves have displaced in opposite directions

Explanation:

Interference occurs when two waves meet at a point in space. When this occurs, two extreme conditions can occur:

- if the two waves are in phase (=displacement in the same direction), the amplitude of the resultant wave is equal to the sum of the amplitudes of the two waves:

A = A1 + A2

and this condition is called constructive interference

- if the two waves are in anti-phase (=displacement in opposite directions), the amplitude of the resultant wave is equal to the difference of the amplitudes of the two waves:

A = |A1 - A2|

and this condition is called destructive interference. Note that if A1=A2, the amplitude of the resultant wave is zero.

6 0

3 years ago