Atomic and Nuclear Physics Answers

NaCl has a melting point of 800 ºC and MgO has a melting point of 2800 ºC.
How would you explain these facts?

The de Broglie wavelength of an electron in the first Bohr orbit is

Physics Iceberg question?

The volume of an iceberg is 664,000 ft^3.

(a)
What is its weight (in lb), assuming it is pure ice? (Round your answer to at least four significant figures.)
____ lb

(b)
What is the volume of seawater (in ft^3) it displaces when floating? (Hint: You know what the weight of the seawater is. Round your answer to at least three significant figures.)
____ ft cubed

(c)
What is the volume of the part of the iceberg out of the water (in ft^3)?
____ ft cubed

Thank you for the help!

Physics buoyancy question?
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A juniper-wood plank measuring 0.46 ft by 1 ft by 14 ft is totally submerged in water.

(a) What is its weight?

_____ lb

(b) What is the buoyant force acting on it?

_____ lb

(c) What is the size and the direction of the net force on it?
size
_____ lb

... direction up or down?

Physics question?

A large tanker truck can carry 21 tons (42,000 lb) of liquid.

(a)
What volume of antifreeze (in ft^3) can it carry?

_____ f^t3

(b)
What volume of pure water (in ft^3) can it carry?

_____ ft^3

Physics question on volume and weight?

A certain part of an aircraft engine has a volume of 1.6 ft^3.
(a) Find the weight of the piece when it is made of silver.
____ lb

(b) If the same piece is made of aluminum, what is its weight?
____ lb

Determine how much weight is saved by using aluminum instead of silver.
____ lb

Physics Mass Density problem! HELP!!?

A box-shaped metal can has dimensions 14 in. by 4 in. by 5 in. high. All of the air inside the can is removed with a vacuum pump. Assuming normal atmospheric pressure outside the can, find the total force (in lb) on one of the 4-by-5 in. sides. (Enter the magnitude.)

______lb

A photon of light with a wavelength of 433 nm is emitted from an excited hydrogen atom. Through what transition did the electron in this atom undergo?

A small particle moves horizontally at 3.0 x10^6 m/s and entered a downward electric field produced by two horizontal plates, 2.0 mm apart, connected to a 40-V battery. If the charge-to-mass ratio of the particle is 1.0 x10^8 C/kg, what is the instantaneous acceleration?

an 80-N force has been applied to a block and move it 20 m along the direction of the force. How much work has been done to the block?