Physics Answers

A light of wavelenght 400 nm passes from air to water. a. what is the frequency of light in water? b. What is the speed of light in water if its index of refraction is 1.33 ? c. What is the wavelength of light in water?

A 1.50kg object hangs motionless from a spring with a force constant of k=250N/m how far is the spring stretched from its equilibrium length?

An astronaut sent on a mission to a new planet where the gravitational field strength near the surface is 3.9 N/kg. Using actual mass, find the weight and mass of the astronaut (a) on earth (b) on the new planet and (c) in space.

A 5.0m long ladder who weighs 180N rests against a vertical wall, making an angle of 53 degrees with the ground. When a person who weighs 800N climbs this uniform ladder and stops one-third of the way up the ladder. Find the normal and frictional forces on the ladder at its base.

Given that the potential energy of a pair of atoms in a solid is raised by 1 eV when their

separation is changed by 1Å, calculate the macroscopic elastic modulus of the lattice.

An aluminum cylinder has a volume of 60ml. Calculate the buoyant force that will be exerted on the cylinder when it is interested in

A. Water

B. Alcohol (density=0.78g/ml)

If you leave your house at 2.47pm

and travel for one and three quarter

hours, what time will you arrive at your

destination?

A balloon has a total volume of 6,000 cm3

and a mass of 3.5 g. Find the buoyant force of the 

air on it, in dyne unit. Note that 1 dyne = 1 g.cm/s2

(Density of air = 0.00129 g/cm3)

Gauge length prior to starting =50mm

Length after fracture =66.4mm

0.1% proof load=18.5kn

Maximum load=26.6kn

Original diameter =10mm

Calculate using the above data the

2. 0.1 proof stress

3. Tensile strength

NASA is expected to send a 2600-kg satellite 450 km above the earth’s surface.What speed will it have?(Hint: Earth’s mass is 5.97 x 1024 kg)