do you believe that the universe is expanding?
Answer:
Yes
Explanation:
Many scientists believe that the universe is expanding at an increasing rate. Scientists cannot explain how the universe is expanding at an increasing rate because by law of conservation of energy, there is only a finite amount of energy. Thus, scientists have called this new source of energy dark matter and it is all around the universe helping shape and form the universe.
If no braking occurs, a total of how much power would be required to keep the railcar moving at 40 m/s
Answer:
40 kW
Explanation:
A railcar has a continuous 1000 N decelerating force any time it is in motion. If no braking occurs, how much power would be required to keep the railcar moving at 40 m/s
Solution:
Power in Physics is the rate of doing work and the work can be mechanical, electrical, etc. The S.I unit of power is the watts (W).
The power required to keep the car moving must match the work done by the friction force (decelerating force) that tends to slow down the railcar.
Work done = Force * displacement
Power = Work done / time = (Force * displacement) / time
Power = Force * (displacement / time)
Power = force * velocity = 1000 N * 40 m/s = 40000 W
Power = 40 kW
100 POINTS !!! PLEASE HELP !!!!
What is the independent variable?
What is the dependent variable?
I
Materials
1. 4 antacid tablets
2. 2 clear cups labeled Hot and Cold
3. Water
4. Timing device
Answer:
dependent: the outcome of the experience
independent variable: everything literaly.
Independent is where you change some variables and see the result
Dependent is literaly the result, or the outcome dependent on the exprience.
Explanation:
I got u.
(a) What is the escape speed on a spherical asteroid whose radius is 301 km and whose gravitational acceleration at the surface is 0.412 m/s2
Answer:
[tex]V.E=498.02m/s^2[/tex]
Explanation:
From the question we are told that:
Radius [tex]r=301Km[/tex]
Gravitational acceleration [tex]g=0.412 m/s^2[/tex]
Generally the equation for Escape velocity is mathematically given by
[tex]V.E^2=2gr[/tex]
[tex]V.E^2=2*0.412m/s^2*301000[/tex]
[tex]V.E^2=248024[/tex]
[tex]V.E=\sqrt{248024}[/tex]
[tex]V.E=498.02m/s^2[/tex]
What is the direction of the magnetic field due to the positive charge at the location of the negative charge
Answer:
A positively charged object moving due west in a region where the Earth's magnetic field is due north experiences a force that is straight down as shown.
A negative charge moving in the same direction would feel a force straight up.
. A car accelerates uniformly from 0 to 72 km/h in 11.5 seconds.
a) What is the acceleration of the car in m/s2? b) What is the position of the car by the time it reaches the velocity of 72 km/h?
Answer:
Explanation:
First job is to convert 72 km/hr to m/s:
[tex]72\frac{km}{hr}[/tex] × [tex]\frac{1000m}{1km}[/tex] × [tex]\frac{1hr}{3600s}[/tex] = 2.0 × 10¹ m/s
Now to find the acceleration which is
[tex]a=\frac{v_f-v_0}{t}[/tex] and filling in:
[tex]a=\frac{2.0*10^1-0}{11.5}=1.7\frac{m}{s^2}[/tex] That's part a. Part b want to know how far the car can get in 11.5 seconds (because that's the time it takes for the car to get to 72 km/hr). Since we know that the car can get 2.0 × 10¹ meters in 1 second, that means that in 11.5 seconds, the car can get 11.5(2.0 × 10¹) which is 230 meters.
What is the tangential speed of a point on a wheel of a car if the point is located 0.114 m from the axis of rotation; and the wheel is rotating at 6.53 rev/sec?
Answer:
Tangential speed = R * w where w is the angular speed
For a wheel v = .114 m * 6.53 / sec = .744 m/s
Note that this is the tangential speed - If the wheel were moving at speed V then as viewed from the ground you have
top V + v
bottom V - v
That is the wheel also has speed due to the speed of the axle (axis of rotation)
Which contributions did Galileo make to the model of the solar system? Select two options.a mathematical model for the orbits of the planetsscientifically accurate data on planetary orbitsdata that showed that planets reflected sunlight similar to Earth’s moonthe idea that stars are other suns that do not moveobservations of the moons of Jupiter rotating around the gas giant
Answer:
Data that showed that planets reflected sunlight similar to Earth's moon
Observations of the moons of Jupiter rotating around the gas giant
Explanation:
Two of Galileo's contributions to the model of the solar system which he was able to observe with the aid of a early version of the modern telescope which he built himself, following the invention of the 'spyglass' are;
1) The phases of Venus motion round the Sun which is similar to the motion of the moon round the Earth that showed that planets in orbit of the Sun reflected sunlight like the Moon
2) The four moons that rotate around Jupiter.
Answer:
it C and E or 3 and 5
Explanation:
Why are the largest craters we find on the Moon and Mercury so much larger than the largest craters we find on the Earth
Answer:
Because Moon and Mars has no atmosphere.
Explanation:
Moon and Mars has no atmosphere, so there is no friction on the falling object due to the atmosphere. The speed of the falling object is more at Moon and Mars.
When a small object impact on the surface of moon or Mars with high speed, the size of crater is large than the earth as out earth has atmosphere.
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)
a man is running on the straight road with the uniform velocity of3m/s.calculate its acceleration
Answer:
9m is this the way calculator its acceleration
A man is running on the straight road with the uniform velocity of 3 m/s.
To find out:Acceleration produced by the man.
Solution:Given, the man is running with uniform velocity of 3 m/s.So the velocity did not change.It remains constant.We know, acceleration is the change of velocity per unit time.Since there is no change in velocity in this case, so there will be no acceleration.So, the acceleration produced by the man is zero.Answer:The acceleration produced by the man is zero.A 25.0kg girl pushes a 50.0kg boy with a force of 100.0N. What is the acceleration of the girl?
Answer:
im pretty sure it should be 50.0
person has a mass of 60kg. How much do they weigh on Earth, if the gravitational field strength is 10 N/kg?
Answer:
588n is the answer may be
a 2kg object is dropped from height of 10m. ignoring air resistance calculate:
1. mechanical energy of the object
2. kinetic energy of the object when it is 3m above the ground
Answer:
ME= 196.2 J
KE= 136.2
Explanation:
potential energy=mgh 2*9.81*10
Our ME is quivalent to PE as that is the toal amount of energy in the system
Kinetic energy= 1/2 m[tex]v^{2}[/tex]
to solve for kinetic enrgy we need to use a kinaetmtic equation that help us find velocity
vf= vi+at
but we need to find time first
d=vi+1/2(accelretaion)[tex]t^{2}[/tex]
7=0+1/2(9.81)[tex]t^{2}[/tex]
t= 1.19 s
vf= 0+ 9.81*1.19
vf= 11.67 m/s
Now
1/2 m[tex]v^{2}[/tex]
1/2*2*[tex]11.67^{2}[/tex]
= 136. 2
or we could just (PE/10)*7
so (196.2/10)*7
Calculate the distance travelled by the car in part Q use the equation distance travelled= average speed x time
Explanation:
distance travelled = average speed x time
=30m/s*100s
=3000m
Answer:
3000m
Explanation:
30m/s*100s
3000m
What is Unit and standard unit?
Answer:
The standard quantity with which we carry out the measurement of any physical quantity of the same kind is called a unit.
If the resistance is 25 and the voltage is 75. What is the amount of current that I will be getting?
Answer:h
Explanation:
When your vehicle turns a corner, the tracks made by the rear tires are always: a) Outside of those made by your front tires b) Inside of those made by your front tires c) On top of those made by your front tires d) None are correct
Answer:
I think it's D
Explanation:
because I have seen the tracks of the tires
Select the correct answer from each drop-down menu.
An object that’s
charged has more electrons than protons. An object that’s
charged has fewer electrons than protons. An object that’s
charged has the same number of electrons and protons.
Answer:
(1) An object that’s negatively charged has more electrons than protons.
(2) An object that’s positively charged has fewer electrons than protons.
(3) An object that’s not charged has the same number of electrons than protons.
Explanation :
Objects have three subatomic particles that are Electrons, protons, and neutrons.
Protons and neutrons are found in the nucleus and electrons rotate or move outside the nucleus. Naturally, protons are positively charged, neutrons have no charge, and electrons are negatively charged.
Therefore, an object that is negatively charged has more electrons than protons. An object that is not charged has the same number of electrons than protons. An object that is positively charged has fewer electrons than protons.
The amount of solar radiation received by Earth from the sun, known as _______________________, is greatest when the sun is directly overhead a location. (Answer must be correctly spelled and is case sensitive).
The amount of solar radiation received by Earth from the sun, known as insolation, is greatest when the sun is directly overhead a location.
The amount of solar radiation received by Earth from the sun is known as insolation, solar insolation is greatest when the sun is directly overhead a location.
What is solar energy?The energy transferred from the Sun in the form of electromagnetic radiation is known as the solar energy
It can be used as thermal energy for various life purposes as well as for electricity conversion with the help of solar photovoltaic cells
The ratio of total electrical energy generated by a solar photovoltaic panel to its total thermal energy is known as solar energy efficiency. The solar panel's area and design have an impact on how energy-efficient it is.
Thus, the term "insolation" refers to the amount of solar radiation that Earth receives from the sun. Solar insolation is highest when the sun is directly overhead a location.
Learn more about solar energy from here, refer to the link;
brainly.com/question/9704099
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A wave travels at 330m/s^-1. the wavelength is found to be 2.4m.
Calculate the period of oscillation of a article in the medium transmitting the waves.
The frequency of oscillations of the source transmitting the wave
Answer: frequency 137.5
Time period 0.01sec
Explanation:
In uplifting 750 newton load with the help of 2 meter long lever lever took 250 newton efforts . What will be the efficiency of a machine if the fulcrum is kept 50 cm from the load
Answer:
the efficiency of the machine is 100%
Explanation:
Given;
load, L = 750 N
length of the lever, L = 2 m
effort applied, E = 250 N
Position of the load from the fulcrum, = 50 cm
50cm
0↓--------------------------Δ-------------------------------↓---------200 cm
750 N x cm 250 N
Apply the principle of moment;
750(50) = 250(x)
x = (750 x 50) / (250)
x = 150 cm
the distance of the effort = 150 cm = 1.5 m
the distance of the load = 50 cm = 0.5 m
The velocity ratio of the machine = 1.5/0.5
= 3
The mechanical advantage of the machine is calculated as;
M.A = Load/effort
M.A = 750 / 250
M.A = 3
The efficiency of the machine is calculated as;
E = (M.A / V.R) x 100%
E = (3/3) x 100% = 100%
Therefore, the efficiency of the machine is 100%
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%
pahelp po ako.
1. Which of the following terms refers to energy in motion?
A. kinetic energy C. potential energy
B. light energy D. thermal energy
2. Which of the following is a type of energy gained due to its position?
A. kinetic energy C. gravitational potential energy
B. light energy D. thermal energy
3. How do you get the total mechanical energy of an object in a closed system?
A. Get the sum of the initial and final kinetic energy.
B. Get the sum of the initial and final potential energy.
C. Get the sum of the kinetic energy and the potential energy.
D. Get the difference between the kinetic energy and the potential energy.
4. Which of the following is the best set up to observe the conservation of mechanical energy?
A. A cart rolling down a wooden ramp.
B. A wooden block falling in a vacuum.
C. A volleyball falling from a tall building.
D. a paper plane being launched from a tower.
5. A big rock was dropped from the third floor of a building. What happens to the kinetic energy of the ball as it falls?
A. The rock’s kinetic energy increases.
B. The rock’s kinetic energy decreases.
C. The rock’s kinetic energy remains the same.
D. The rock’s kinetic energy cannot be identified.
6. A heavy metallic ball was rolled up on a frictionless ramp. What happens to the gravitational potential energy of the ball as it rolls up the ramp?
A. The ball’s gravitational potential energy increases.
B. The ball’s gravitational potential energy decreases.
C. The ball’s gravitational potential energy remains the same.
D. The ball’s gravitational potential energy cannot be identified.
7. A 2kg ball is elevated up a building, how much is its potential energy 10m from the ground?
A. 5J C. 98J
B. 20J D. 196J
For items 8 to 10, refer to the illustration below. A ball is dropped at point W and travels along a frictionless path to reach point Z.
8. At which point does the ball has greatest gravitational potential energy?
A. W C. Y
B. X D. Z
9. At which point does the ball has greatest kinetic energy?
A. W C. Y
B. X D. Z
10. What happens to the total mechanical energy of the ball as it travels from point W to point Z?
A. The total mechanical energy increases.
B. The total mechanical energy decreases.
C. The total mechanical energy remains the same.
D. The total mechanical energy cannot be determined.
For items 11 to 12, refer to the illustration below. A pendulum swings back and forth from its highest position to its lowest position and vice versa.
11. As a pendulum swings from its highest to lowest position, what happens to its gravitational potential energy and kinetic energy?
A. Both its GPE and KE increases.
B. Both its GPE and KE decreases.
C. Its GPE decreases but KE increases.
D. Its GPE increases but KE decreases.
12. What happens to the total mechanical energy of the bob as it swings back and forth if only force acting on it is the gravitational force?
A. The total mechanical energy increases.
B. The total mechanical energy decreases.
C. The total mechanical energy remains the same.
D. The total mechanical energy cannot be determined.
Four ball of masses 0.5 kg, 1 kg, 2 kg, and 5 kg were dropped simultaneously on top of a building with the height of 20 m. Ignoring the air resistance, the four balls reach the ground at the same time.
13. Which of the following balls has the greatest gravitational potential energy on top of the building?
A. The ball with the mass of 5 kg.
B. The ball with the mass of 2 kg.
C. The ball with the mass of 0.5 kg.
D. All the balls have the same potential energy.
14. Which of the following balls has the least kinetic energy on top of the building?
A. The ball with the mass of 5kg.
B. The ball with the mass of 1kg.
C. The ball with the mass of 0.5kg.
D. All the balls have the same kinetic energy.
15. Which of the following balls has the greatest total mechanical energy?
A. The ball with the mass of 2kg.
B. The ball with the mass of 1kg.
C. The ball with the mass of 0.5kg.
D. All the balls have the same total mechanical energy
The rear wheels of a tractor are very wide. Why?
Answer:
The rear wheels of a tractor are very wide so that the weight of the tractor spread over the greatest surface area possible ,so it doesnot sink into the soil.please as brainliest
A boy travels 12km east wards to a point B and then 5km southwards to another point C. Calculate the difference between the magnitude of the displacement of the boy and the distance travelled by him.
Explanation:
pls mark me as brainliest
If a boy travels 12 km eastwards to a point B and then 5km southwards to another point C, then the difference between the magnitude of the displacement of the boy and the distance traveled by him would be 4 kilometers.
What is displacement?An object's position changes if it moves in relation to a reference frame, such as when a passenger moves to the back of an airplane or a professor moves to the right in relation to a whiteboard. Displacement describes this shift in location.
As given in the problem a boy travels 12km eastwards to a point B and then 5km southwards to another point C.
Distance traveled = 12 + 5 = 17 km
The displacement = √ ( 12² + 5² )
= 13 km
Thus, If a boy travels 12 km eastwards to a point B and then 5km southwards to another point C, then the difference between the magnitude of the displacement of the boy and the distance traveled by him would be 4 kilometers.
To learn more about displacement here, refer to the link given below;
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physics class 9 chapter 8 please tell please
Answer:
(a) The motion is uniform
(b) 11.11 m/s
Explanation:
(a)
From the table below, the motion of the bus is uniform.
(b)
Speed(s) = Δd/Δt
s = Δd/Δt............. Equation 1
From the table,
Given: Δd = 10 km = 10000 m, Δt = 15 minutes = (15×60) = 900 seconds
Substitute these values into equation 1
s = 10000/900
s = 11.11 m/s
A car going around a curve with a radius of 15m experiences a centripetal acceleration of 2.5 m/s2. How fast is the car going?
0.17m/a
38 m/s
6.1 m/s
6.0 m/s
Answer:
Explanation:
The formula for centripetal acceleration is
[tex]a_c=\frac{v^2}{r}[/tex] . Filling in:
[tex]2.5=\frac{v^2}{15}[/tex] and
[tex]v=\sqrt{2.5(15)}[/tex] so
v = 6.1 m/s
a stone of mass 250kg and another stone of mass 400 kg are kept at a distance of 100m what amount of gravitational force develops between them?
Explanation:
Hey there!
Given;
Mass of one object (m1) = 250kg
Mass of another object (m2) = 400 kg
Distance (d) = 100 m
Gravitational constant (g) = 6.67*10^-11
Now;
[tex]f = \frac{g.m1.m2}{ {d}^{2} } [/tex]
Keep all values;
[tex]f = \frac{6.67 \times {10}^{ - 11} \times 250 \times 400}{ {(100)}^{2} } [/tex]
Simplify
[tex]f = \frac{6.67 \times {10}^{ - 11} {10}^{5} }{10000} [/tex]
[tex]f = \frac{6.67 \times {10}^{ - 6} }{10000} [/tex]
Therefore, gravitational force is 6.67*10^-10.
Hope it helps!
Atoms contain both positive nuclei and a negative electron cloud. Which of the following would cause an attraction between two atoms?
A. The nucleus of one atom and the electron cloud another atom
B.The nucleus of one atom and the nucleus of another atom
C. The electron cloud of one atom and the electron cloud of another atom
D.None of these would cause an attraction between atoms
Answer:
Option (D)
Explanation:
A. The nucleus of one atom and the electron cloud of the another atom will not the cause of attraction.
B. The nucleus of one atom and the other atom will not cause the attraction.
C. The electron cloud of one atom and the electron cloud of the another will not cause attraction.
D. So, this option is correct.