is sand a solid or a liquid and why?

Can someone tell me about energy and potential energy

An object of mass 20kg is falling in air and experiences a force due to air resistance of 40N. Determine the net force acting on the object and calculate the acceleration of the object.

The length of the wing of an air plane is 10 m. Its horizontal velocity is 200 m /s. If the vertical component of the earth’s magnetic field is 5.0 × 10^-5 weber /m2, calculate the potential difference developed across the two ends of the wing.

an L.E.D bike light that produces 95% light and only 5% heat

A track team is practicing for a 4 x 100 m relay race. The first runner, Linda, is running at a constant speed of 8.6 m/s. The next runner, Jenny, will be starting from rest at the 80 m mark. She has an acceleration of 1.0 m/s2. Ideally the two runners meet at the 100 m mark to hand over the baton. At this point, Jenny is still accelerating.

a) At what distance behind Jenny should Linda be when Jenny starts running? (Assume for simplicity that there is no distance between the two runners when the switch happens.)

b) How long does it take Jenny to run from the 80-m mark to the 100-m mark?

c) What’s Jenny’s speed at the 100m mark? Linda Jenny

I need to know how can sorters works. They pick up steel cans but not aluminium ones. Why?

I need to mention the works like magnetism, electromagnets

Calculate the ground state energy of the B4+ ion (i.e. for n = 1), and the energy of the next four highest energy levels (i.e. for n = 2, 3, 4, 5).

My answers are:- boron z=5

n=1 E1 = -340 eV n=2 E2 = -85 eV n=3 E3 = -37.78 eV n=4 E4 = -21.25 eV n=5 E5 = -13.6 eV

Are these right? thanks for your help.

1kg water closed system -isothermal heat intake process initial pressure 15bar dryness 25%. Then expansion to 1bar and 84.9 dryness. What is heat input and work done at isothermal stage? What is heat intake at beginning of heat rejection process?

deduce expression for resistance

Discribe an experiment you would carry out in order to determinethe density of a stone?

describe iron

describe steel

the displacement of an object of mass m after time t when a net force F acts on it is dependent on F, t and m. use dimensional analysis to work out the formula for the displacement of the object.

does nuclear energy benefits the energy production

could you teach me physics in topic Electricity?

hey i am doind a piece of homework on electromagnets and i have to reaserch 3 examples and i have already done scrap yard can i have some help?

Deduce the expression for the electric field E due to a system of two charges q1 and q2 with position vectors r1 and r2 at a point r with respect to common origin.

A hammer head with mass 0.5 kg strikes the head of a nail at a speed of 10m/s .The nail is driven 1 cm into a piece of wood. What is the average force on the nail?

The weight of a rider, driving scooter is assumed to be evenly distributed on both the tyres. The area of contact of each type with the ground is 10 cm2. If the pressure inside the tyres is 3 bar, find the mass of the rider (g = 10 ms−2)

i dont understand halflife. I just dont understand the concept but i understand radioactive decay.

What can you say about the rate of heat energy transfer in an object that is at the same tempreature as it's surroundings

why is water used to cool car engines?

What is the difference between latent heat of fusion and latent heat of vapourisation?

heat capacity is measured in what

I have a table of values for a projectile moving away from a radar station. My first column is the time (t) of 0 to 60 with time steps of 4. I then have a distance(km) of the projectile from the radar station followed by the angle(radians) of the projectile to the radar station.

The distance obviously increases by time along with a lowering of the angle of the projectile to the radar station.

I need to write a program which will work out the magnitude of velocity and acceleration for each time step (each 4 seconds upto 60) as the projectile moves away. I am confused how to do this because I am unsure how to approximate the derivatives. I can give further data and formulas if required. The program is the easy bit but I just don't know how to get the write answers into Excel first so I can work out how to program it correctly.

I need to do a presentation on Magnetism. The presentation needs to be enjoyable and informative. Basically I am sposed to teach them but I dunno wat to do. Any ideas?

Carol eats a regular hamburger and drinks a glass of cow's milk for breakfast. Suppose that energy content of the hamburger and the milk are 2115 kJ and 565kJ respectively. What % of energy from the food does Carol use to push a sack of rice along a horizontal distance of 4.75 m? Her hands exerted a force of 50N applied 20° down with the horizontal.

I need to know how these work in relation to thermal transfers and the kinetic theory?

I have already failed two and another one is coming up soon can you help me?

The question paper and experiment don't seem to link?

How large is the moon in comparison to the Earth? And would this have any bearing on our seasons if it was larger?

1. Two cars are travelling on a straight stretch of highway at a steady 110 km/h in the same direction. Drivers are advised to maintain a separation of about 3 seconds between cars (more in poor road conditions). How far apart should the two cars be in meters (give you r answer to the nearest meter).

How do we know the difference between the lenses. And what is the focal length?

if the sun was bigger would it give us more heat

Hi, my son is a first year undergrad student studying Chemical Engineering. He is having difficulties understanding Fluid Dynamics. Am looking for an online tutor to help him.

to find the volume of an irregular shaped wooden piee a sinker made of steel (relative density = 7.85) having a mass of 157 g was used. if the levels of water before and after immersing the sinker wood ombination are 102 ml and 170 ml respectively then find the volume of woodewn piece

How do you go about converting prefixes? example: 320J______kJ

a small block is pulled along a rough horizontal surface at a constant speed of 3m/s by a constant force. The magnitude of the force is 30N and acts at an angle of 30 degrees to the horizontal. Calculate the work done by this force in 10 seconds

what does basically momentum mean? what is elastic and inelastic momentum? please, if possible, answer the first question at first.

A 1000kg car speeds up on the street at 72km/h. It suddenly brakes with a constant force of 5x103 N. How far the car will travel from the moment it brakes till it completely stops?

what's live example of newton's 3rd law?

A polonium-210 atom has mass 3.5x10^-25kg and each decay from one of these atoms produces an energy of 5.3MeV. a) How many decays per second are required to supply a power of 1000W? b) What mass of polonium-210 is required for this power? The decay constant of polonium-210 is 5.8x10^-8

if a star is 5.2x1016 meters away, what is the parallax angle in degrees?

Just need a step by step answer to confirm that my answer of 0.000165598290 is correct ( note that the second five and zero have a recurring symbol above each)

I used the conversion 1parsec= 3.1x1016m in my calculation

any help would be much appreciated

The following is a summary of a nuclear fission reaction: 235 1 →unknown nucleus A (Equation 1) 92 U On

unknown nucleus A → 90 Sr + unknown nucleus B + 3 1n (Equation 2) 38 O

Can you help find the mass number and atomic number for the unknown nuclei A and B to identify them. can you explain this to me and how you got worked this out, thank you most sicnerely.

I have done some workings but think it may be incorrect

How can we calculate the work done by a tension force a solid at time t ?

What is physics

Without using your spring scale, estimate the order of magnitude of the mass of your calculator in grams from what you judge to be its size, using the fact that the density of water is 1 g/cm3. Assume that the density of water is about the same as the density of your calculator. 1 g 102 g 104 g 106 g

I need an experiment to test this-the output of an solar cell depends on the are of a solabr cell exposed to light. Help anyone? Also need a website with it on. 🙂

how does pressure in fuids work?

I have been asked to list 6 properties which I think the ideal energy resource should have for generating electricity in a power station. So far I have: Clean and pollution free Efficient allowing the majority of the energy to be harnessed Cheap to source, refine, store and transport Plentiful and renewable Safe to use, store and transport

Do those sound ok so far? I can't think of a 6th one but was considering putting easy to transport to homes but with the question stating that it is for generating electricity in a power station that already accounts for the transport.

How to find the ground state for electron that is in harmonic potential when the potential is given. I know that you use schödingers equation and wave function, but thats all. Otherwise cant solve it!

I need help on understanding what redshift is and what the charts mean

What equal lengths of iron wire and a lead wire, each of 1 mm diameter must be joined in parallel to give an equivalent resistance of 2 ohm ? Resistivity of iron and lead are 10 and 49 micro ohm-cm respectively.

  What expands and contracts when getting hotter and colder in your house and garden?

You are in a snowball fight, and throw a snowball at a high angle over level ground. While your opponent is watching this first snowball, you throw a second one at a low angle timed to arrive before or at the same time as the first one.

Assume both snowballs are thrown with a speed of 39.4 m/s. the first one is thrown at an angle of 71 degrees to the horizontal. What angle should the second snowball be thrown to arrive at the same point as the first?

my question is- "A around wave of frequency 220 Hz travels along a steel bar. Its wavelength is 25 m. How fast is the wave travelling?"

A roller coaster car with a mass of 250kg starts from a height of 100m above the ground just before rolling down the frictionless track. Find the speed of the car as it reaches the ground

Falling objects drop with an average acceleration of 9.8m/sec/sec. If an object falls from a tall building, how long will it take before it reaches a speed of 7m/s?

State the two effects that absorption of electromagnetic radiation can have on the substance that absorbs it

what is topping disance

A sample of steel was tested under large loads and the following stress strain graph was plotted Calculate the young modulus of the steel