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Why don't pendulums work at sea?

Question #2f088

How would you calculate the speed at which the moon revolves around the earth in m/s?

Question #af0b9

A copper wire is wrapped 65 times around an unknown core of length 28cm. The current in the wire is 800mA and the magnetic field due to the electromagnet is 1.63 x 102T. What is the most likely material the wire is wrapped around?

What is the order of the stellar spectral classes?

The halflife of arsenic81 is 33 seconds. Suppose you have 100 g  how much will remain undecayed after 12.5 days?

How do you increase the mechanical advantage of a thirdclass lever?

An object with a mass of #6 kg# is hanging from a spring with a constant of #12 (kg)/s^2#. If the spring is stretched by # 1 m#, what is the net force on the object?

Question #cd675

What it the current value of the Hubble constant and why is the value so important?

How is it that you can have both water and ice at 0 °C and both water and steam at 100 °C?

Poisuille is sI unit of viscosity ? And one pois e is equal to ?

Question #27f28

How do I solve this gas problem?

A room is at a constant temperature of 300 K. A hotplate in the room is at a temperature of 400 K and loses energy by radiation at a rate of P. What is the rate of loss of energy from the hotplate when its temperature is 500 K?

Question #37681

The minimum distance from the origin to the intersection of #x^2+y^2= z# with the plane #x+y+z=12# ?

Question #a1b58

Can the wavelength of light change?

Why does the workenergy theory ignores potential energy?

Question #01f3b

How did scientists come up with the Theory of the Big Bang?

Why do metals feel cold even when they are at room temperature?

As the universe is expanding, is the solar system also expanding?

Question #326d7

Question #8db2f

A tennis ball is thrown from a height #h# above the ground. If the coefficient of restitution #e#, what height will the ball achieve after the third collision ??

Does the white dwarf star rotate?

Can someone explain me how this 1.8F came? I know that change in temperature in Celsius scale is equal to change in temperature in Kelvin scale. But, what about Fahrenheit scale?

Question #5a7d9

Is the sun getting bigger?

What is the difference between hot dark matter and cold dark matter? What difference does it make to cosmology?

What is the significance of negative sign of electronic energy?

Some very hot rocks have a temperature of #630 ^o C# and a specific heat of #270 J/(Kg*K)#. The rocks are bathed in #45 L# of boiling water. If the heat of the rocks completely vaporizes the water, what is the minimum combined mass of the rocks?

What torque would have to be applied to a rod with a length of #4 m# and a mass of #2 kg# to change its horizontal spin by a frequency #8 Hz# over #8 s#?

Question #2f088

What are spiral nebulae? How did they get their name?

How can we derive Kirchoff's current law and Kirchoff's voltage law?

Question #0c95e

If the diameter of a circle has endpoints A(7, 2) and B(1, 8), where is the center of the circle?

Question #edf16

If some galaxies in the local group exhibit blueshift spectral lines, why aren't these blueshifts violations of the Hubble's law?

What is the average lifespan of a star?

If the sun and stars are supported by gas pressure, what supports a white dwarf?

On the WMAP image of the cosmic microwave background radiation, are the higher density irregularities the brighter bits or the darker bits?

If the earth were a mile closer to the sun how would it affect our temperature on earth? How far would the earth have to be from it's current orbit to notice a temperature change?

A #7 L# container holds #12 # mol and #18 # mol of gasses A and B, respectively. Every three of molecules of gas B bind to one molecule of gas A and the reaction changes the temperature from #350^oK# to #175 ^oK#. By how much does the pressure change?

How do you determine if the equation #y=90(5)^x# represents exponential growth or decay?

What is an ellipse?

Question #d496b

Question #aa702

Why can’t we determine the distances to galaxies using the geometric method of trigonometric parallax ?

Question #72b9c

What properties of sound waves might determine how loud a sound is?

What is bigger: a globular cluster or a nebula?

Could I measure the moment of inertia of a fidget spinner by making it the bob of a pendulum? How?

A person 1.80 m tall stands in front of a plane mirror. What is the minimum height of the mirror, and how high must its lower edge be above the floor for the person to be able to see his/her whole body? Person’s eyes are 6.0 cm below the top of the head.

Question #b0e5d

A paddle boat can move at a speed of 2 km/h in still water. The boat is paddled 6 km downstream in a river in the same time it takes to go 3 km upstream. What is the speed of the river?

Why is the temperature of the cosmic background radiation not perfectly isotropic?