Answer:
the change in the internal energy of the balloon is 3,300 J
Explanation:
Given;
heat gained by the balloon system, Q = 6,400 J
work done on the surrounding air by the balloon, W = 3,100 J
The change in the internal energy of the system is calculated from the first law of thermodynamics;
ΔU = Q - W
where;
ΔU is the change in the internal energy of the balloon;
ΔU = 6,400 J - 3,100 J
ΔU = 3,300 J
Therefore, the change in the internal energy of the balloon is 3,300 J
A car is moving at 30km/h. What is its speed in m/s? Give your answer to 2 significant figures.
Explanation is in the attachment
hope it is helpful to you
HELP PLEASE!!
When the same amount of heat is added to equal masses of water and copper at the same temperature, the copper is heated to a higher final temperature than the water. On a molecular level, what explains this difference?
A. The forces between copper atoms are stronger than the forces between water molecules.
B. The average kinetic energy of the water molecules is greater than the average kinetic energy of the copper atoms.
C. More of the heat is transferred to the kinetic energy of the copper atoms than to the kinetic energy of the water molecules.
D. More of the heat is transferred to the potential energy of the copper atoms than to the potential energy of the water molecules.
Answer:
C. More of the heat is transferred to the kinetic energy of the copper atoms than to the kinetic energy of the water molecules.
Explanation:
Both equal masses of water and copper were heated at the same temperature. Since copper is a good conductor of heat compared to water, its absorbs more heat. Which in-turn increases the rate of vibrations of the atoms in the copper mass, thus increasing their kinetic energy.
In the case of water, its molecules displaces one another after being heated to a higher temperature compared to neighboring molecules. So that the heated molecule becomes less dense and floats to the surface of water.
This property of copper makes it to be heated to a higher final temperature than the water.
A scientist wants to use a model to help present results of his detailed scientific investigation
4. A bullet of mass 30 g is fired from a rifle of mass 5kg at a speed of 259m/s.
a) What is the momentum of the rifle just after the bullet is fired?
b) What is the recoil velocity of the rifle?
Answer:
Rifle Momentum=7.77kg*m/s v'= 1.554 m/s
Explanation:
a) m1v1 + m2v2 = m1v1' + m2v2'
0+0 = 0.03*259 + P(rifle momentum)
solve for P
p= 7.77kg*m/s
b) 7.77= 5*v'
v'= 1.554 m/s
The momentum of the rifle just after the bullet is fired is 7.77 kg.m/s and the recoil velocity of the rifle at the time of firing is 1.554 m/s.
What is momentum?
Momentum of a particle is the product of the mass of the particle and its velocity. Momentum is a vector quantity. It has both the magnitude and direction of motion. According to the Newton's second law of motion, the rate of change of the momentum is equal to the force acting on the particle which is in motion.
Momentum can be calculated by the general formula
p = m.v
where, p = momentum of the particle,
m = mass of the particle,
v = velocity of the particle.
Rifle Momentum= mass × velocity
P = m × v'
a) m1v1 + m2v2 = m1v1' + m2v2'
0+0 = 0.03 × 259 + P(rifle momentum)
0 = 7.77 + P
P = 7.77kg.m/s
b) p = m × v
7.77= 5 × v'
v'= 1.554 m/s
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A car travelling an unbanked curve of radius 200 ft notices a truckstopped on the road ahead. The driverimmediately applies brakes causing the speed of the carto decrease at the rate of 10 ft/s2. If at that instant, the stationary truckis 100 ft ahead (the distance is measured along the path) and the car is travelling at a speed of 40ft/s, whatis the magnitude of the relative velocity ofthe truck perceived by the driver of the car (i.e. from the moving frame of referenceof the car).
Answer:
u = - 40 ft / s
Explanation:
The Galilean relation for the relative velocity is
v ’= v + u
where u is the speed between the two reference frames, v is the speed of the fixed system and v 'the speed of the mobile system.
In this case the truck has a speed with respect to the ground (fixed system) 0 m / s (it is stopped), the car has a speed with respect to the ground of v = 40 ft / s,
u = v'- v
u = 0 - 40
u = - 40 ft / s
the speed perceived by the car if the system is fixed on it is -40 ft / s
what is the meaning of coulomb in physics ????
Coulomb, unit of electric charge in the metre-kilogram-second-ampere system, the basis of the SI system of physical units. ... The coulomb is defined as the quantity of electricity transported in one second by a current of one ampere.
Mark me as brainliest....
Describe the resistance through a
diode
Explanation:
A diode is an electrical element which offers the flow of current freely in one direction with very less resistance.
The given figure depicts a diode in forward bias, where the p-side and the n-side of the diode are connected to positive and negative terminals respectively. In such a case the current flows from the p-side to n-side of the p-n junction very easily and the value of the current increases rapidly after a certain voltage, this voltage is called threshold voltage.
We can deduce from the graph that the resistance of the diode reduces with increase in voltage. As resistance is given by the formula:
[tex]R=\frac{V}{i}[/tex]
what is the least count of screw gauge and vernier calliper (9th grade) please help!
A woman wearing high heels will find difficult to walk on the sandy beach than if she wears flat sole sandals. Why?
Explanation:
the high heels has a more pressure than flat soles bcoz small area has more pressure than large area.
What is the distance to school if it took bob 1 hour to get to it going at the speed of 1 km/h.
Answer:
1 km
Explanation:
Bob travels at one km/h and it takes him one hour to get there.
As the motor speeds up, the value of current decreases because of A. Friction loss B. Increase in resistance C. Increase in back emf D. All mentioned above
Answer:
C. Increase in back emf
Explanation:
As the current through the field winding decreases the field strength also decreases and the back-emf is reduced, as a result the motor speeds up.
When the motor begins to speed-up, an additional back EMF is generated due to induction which reduces armature current. This also results in reduced strength of the field flux. The back emf generated is not enough to reduce the armature current which could stop the acceleration of the motor and the motor further accelerates.
A screw Jack whose pitch is 2mm is used to raise a bus of mass 900kg through height of 20cm. The length of the Tommy of the Tommy of the jack is 40cm. Calculate the velocity ratio of the machine
R= 40cm —> R= 0.4 m
P= 2mm —> P= 0.002 m
[tex]V.R = \frac{2πR}{p} = \frac{2 \times 3.14 \times 0.4}{0.002} = 1256[/tex]
I think this is the answer
I hope I helped you
Good luck ^_^
When the motion of one or both of the particles is at an angle to the line of impact, the impact is said to be ________
Answer: Oblique impact
Explanation:
When the motion of one or both of the particles is at an angle to the line of impact, the impact is said to be oblique impact.
On the other hand, when the directions of motion of the two colliding particles are moving along a line of impact, then it's refered to as central impact.
The calculated value of static friction
A) increases as force increases
B) is the amount of friction present for an object at rest
C) causes a net acceleration
D) is the maximum value possible
A car initially traveling at 60 km/h accelerates at a constant rate of 2.0 m/s2. How much time is required for the car to reach a speed of 90 km/h
Answer:
Time, t = 4.165 seconds.
Explanation:
Given the following data;
Initial velocity = 60 km/h
Final velocity = 90 km/h
Acceleration = 2 m/s²
Conversion:
60 km/hr to meters per seconds = 60*1000/3600 = 60000/3600 = 16.67 m/s
90 km/hr to meters per seconds = 90*1000/3600 = 90000/3600 = 25 m/s
To find the time, we would use the first equation of motion;
[tex] V = U + at[/tex]
Where;
V is the final velocity.
U is the initial velocity.
a is the acceleration.
t is the time measured in seconds.
Making time, t the subject of formula, we have;
[tex] t = \frac{V - U}{a}[/tex]
Substituting into the equation, we have;
[tex] t = \frac{25 - 16.67}{2}[/tex]
[tex] t = \frac{8.33}{2}[/tex]
Time, t = 4.165 seconds.
A shell is fired at an initial speed of 2500 m/s at an initial angle of 45 degrees. Find the shell's horizontal range and the amount of time the shell is in motion. (note that because it is fired from the ground to the ground, they displacement = 0.)
Answer:
d= 637323 meters
t= 360.5 seconds
Answer:
Explanation:
Since the height from which the shell was fired is the same as the height at which it lands (on the ground, to be specific), we will use the range equation. That is the only time you CAN use the range equation (when the initial height and the final height are exactly the same). The range equation is:
[tex]r=\frac{v_0^2sin(2\theta)}{g}[/tex] where v0 is the initial velocity, theta is the angle, and g is the pull of gravity (NOT negative). Filling in:
[tex]r=\frac{(1500)^2sin(9.0*10^1)}{9.8}[/tex] so, doing all that math gives us:
r = 6.4 × 10⁵ meters
A planet has a circular orbit around a star. It is a distance of 53,000,000 km from the centre of the star.
It orbits at an average speed of 49,000 km/h.
How many Earth days does it take the planet to orbit the star?
Give your answer to 2 sf.
Answer:
it takes 365 days to revolve around the star(sun)
How many more neutrons are in a I SOTOPE of copper-14 than in standard carbon atom
Answer:
2 more neutrons
Explanation:
To obtain the answer to the question, let us calculate the number of neutrons in carbon–14 and standard carbon (i.e carbon–12). This can be obtained as follow:
For carbon–14:
Mass number = 14
Proton number = 6
Neutron number =?
Mass number = Proton + Neutron
14 = 6 + Neutron
Collect like terms
14 – 6 = Neutron
8 = Neutron
Neutron number = 8
For carbon–12:
Mass number = 12
Proton number = 6
Neutron number =?
Mass number = Proton + Neutron
12 = 6 + Neutron
Collect like terms
12 – 6 = Neutron
6 = Neutron
Neutron number = 6
SUMMARY:
Neutron number of carbon–14 = 8
Neutron number of carbon–12 = 6
Finally, we shall determine the difference in the neutron number. This can be obtained as follow:
Neutron number of carbon–14 = 8
Neutron number of carbon–12 = 6
Difference =?
Difference = (Neutron number of carbon–14) – (Neutron number of carbon–12)
Difference = 8 – 6
Difference = 2
Therefore, carbon–14 has 2 more neutrons than standard carbon (i.e carbon–12)
Refer to the periodic table above a student is asked
Answer:
there is no context??????
1) With the aid of diagrams explain how two hollow cans be charged by induction using 5 units of positive charges.
Answer:
plz mark as a pure substance abuse and function of the equation for sulphur dioxideHow energy is obtained due to flow of charges?
what is latent heat of vaporization?
The amount of energy required for a unit mass of a substance to undergo a phase change from liquid to gas.
a ball is launched from the ground with a horizontal speed of 30 m/s and a vertical speed of 30 m/s. what is the balls overall speed at the top of its trajectory?
Answer:
30m/ s
Explanation:
this is an example of a projectile, where the path traced by the ball will be a downward parabola.
one must know that the vertical velocity of an object having projectile motion is zero at the top of its trajectory and that the horizontal velocity remains constant throughout.
this means, at the top of the trajectory the ball's overall speed will be equal to its horizontal velocity.
and horizontal velocity is given 30 m/s
hence, overall speed of the ball = 30m/ s
An instrument rated pilot is planning a flight under IFR on July 10, this year. Before conducting the flight, the pilot must have
Answer: See explanation
Explanation:
From the information given, we are informed that an instrument rated pilot is planning a flight under IFR on July 10, this year.
It should be noted that before conducting the flight, the pilot must have performed and logged the prescribed tasks and repetitions that are required for instrument currency no earlier than January, 10 for the year.
b.
13. What i
c.
In a single movable pulley, a load of 500 N is lifted by applying 300 N effort
Calculate MA, VR and n.
[Ans: MA = 1.66, VR = 2, n = 8
83.33%]
Answer:
MA = 1.66, VR = 2, Efficiency = 83.33%
Explanation:
Given the following
Load = 500N
Effort = 300N
Mechanical Advantage = Load/Effort
MA = 500/300
MA = 5/3 = 1.66
Velocity ratio is the number of pulleyc present in the block and tackle system. Since the pulley is a single movable pulley, then VR = 2
Efficiecncy n = MA/VR * 100%
n = 1.66/2 * 100
n = 166/2
n = 83.33%
kettles heated on stoves used to be made of copper. was this a good choice?
Kettles heated on stoves are used to be made up of copper. This is because copper is a good conductor of heat and electricity.
Why copper is used in making kettles?Copper is used in making kettles. This is because copper is an excellent choice for a tea kettle as it is an excellent conductor of heat and electricity. This means that copper heats up quickly and evenly, making it ideal for the purpose of boiling water and preparing tea. Copper is also a durable material which can last for many years with proper care.
Copper kettles are polished from the outer surface as it is subject to corrosion that is caused by salts and sulfates. If the kettles are not cleaned completely, this corrosion, even as a slight film, will affect the taste of what is prepared in that copper kettle, giving a metallic sensation to taste.
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Imagine you find a venomous snake crawling up your leg after taking a drug that prevented sympathetic nervous system activation. What would the James-Lange theory predict about your experience?
Answer:
I would not feel fear because I haven't had the physiological arousal necessary to induce that emotional state.
Explanation:
The James-Lange theory is a theory of emotions. According to the James-Lange theory, the emotions of a human occur as a result of the physiological reactions to the surrounding events. His theory is one of the well known psychological theories of emotions.
In the context, I took a medicine that prevented the activation of my sympathetic nervous system and imagined a venomous snake that crawls up my leg, I did not feel any fear as I have not had the emotion or the phycological arousal that is necessary to induce the emotional state. It is according the theory of James-Lange.
A rugby player passes the ball 6.8 m across the field, where the ball is caught at the same height as it left his hand. show answer No Attempt 33% Part (a) At what angle, in degrees above the horizontal, was the ball thrown if its initial speed was 12.0 m/s, assuming that the smaller of the two possible angles was used
Answer:
11.86°
Explanation:
Projectile motion is a form of motion where an object moves in parabolic path (trajectory). Projectile motion only occurs when there is one force applied at the beginning on the trajectory, after which the only interference is from gravity.
The range of an object experiencing projectile motion is given by:
R = u²sin(2θ) / g
where u is the initial velocity, θ is the angle with horizontal and g is the acceleration due to gravity
Given that R = 6.8 m, g = 10 m/s², u = 12 m/s.
R = u²sin(2θ) / g
substituting:
6.8 = 13²sin(2θ) / 10
13²sin(2θ) = 68
sin(2θ) = 0.4024
2θ = sin⁻¹(0.4024)
2θ = 23.73
θ = 11.86°
where would the spaceprobe experience the strongest net (or total) gravitional force exerted on it by Earth and Mars
Answer:
r = 41.1 10⁹ m
Explanation:
For this exercise we use the equilibrium condition, that is, we look for the point where the forces are equal
∑ F = 0
F (Earth- probe) - F (Mars- probe) = 0
F (Earth- probe) = F (Mars- probe)
Let's use the equation of universal grace, let's measure the distance from the earth, to have a reference system
the distance from Earth to the probe is R (Earth-probe) = r
the distance from Mars to the probe is R (Mars -probe) = D - r
where D is the distance between Earth and Mars
[tex]G \ \frac{m \ M_{Earth}}{r^2} = G \ \frac{m \ M_{Mars}}{(D-r)^2}[/tex]
M_earth (D-r)² = M_Mars r²
(D-r) = [tex]\sqrt{ \frac{M_{Mars}}{ M_{Earth}} }[/tex] r
r ( [tex]1 + \sqrt{ \frac{M_{Mars}}{M_{Earth}} }[/tex]) = D
r = [tex]\frac{D}{ 1+ \sqrt{\frac{M_{Mars}}{ M_{Earth}} } }[/tex]
We look for the values in tables
D = 54.6 10⁹ m (minimum)
M_earth = 5.98 10²⁴ kg
M_Marte = 6.42 10²³ kg = 0.642 10²⁴ kg
let's calculate
r = 54.6 10⁹ / (1 + √(0.642/5.98) )
r = 41.1 10⁹ m
If your weight is 588N on the earth, how far should you go from the centre of the earth so that your weight will be 300N? The radius of the earth is 6400km and the value of g on the earth surface is 9.8m/s2. please explain....
Answer:
Explanation:
You need something that relates distance to what the gravitational pull is. You can set up a complex sort of proportion. What you need is a number that is comparable to 9.81 or you can just use the Gravitational Force formula with a 4 tier fraction.
Givens
x = the additional distance toward outer space above the radius of the earth.
G is the gravitational constant.
m1 = the person's mass (which does not change no matter where you are).
m2 = the earth's mass
F1 = 588 N
F2 = 300 N
Formula
[tex]\frac{F1}{F2} = \frac{588 N}{300N}=\frac{\frac{Gm1*m2/}{6400^2} }{\frac{G*m1*m2}{(6400 + x)^2} }[/tex]
Solution
G*m1*m2 all cancel. So what you get looks like this.
[tex]\frac{588}{300} = \frac{(6400 + x)^2}{6400^2}[/tex]
Cross Multiply
588 * 6400^2 = 300*(6400+x)^2 Now all you need do is solve for x.
x will be in km.
588*40960000 = 300 * (40960000 + 12800x + x^2)
1.2288*10^10 + 3840000x + 300x^2 = 2.408448*10^10
300x^2 + 3840000x + 1.2288*10^10 = 2.408448 * 10^10
Subtract 2.409448 * 10^10 from both sides.
300x^2 + 3840000x - 1,179648 * 10^10
Now use the quadratic formula
I'm guessing I should have converted this to meters because I'm getting ridiculous numbers. They are already large enough as you can see. The method is correct, even if the numbers are not.
