# Physics: Velocity, Distance, Rotation, Volume, Time, and Speed

Until 1883, every city and town in the US kept its own local time. Today, travelers reset their watches only when the time change equals 1.0h. How far, on the average must you travel in degrees of longitude until your watch must be reset by 1.0h? (hint: Earth rotates 360 degrees in about 24 hours )

Gold, which has a mass of 19.32 g for each cubic centimeter of volume is the most ductile metal and can be pressed into a thin leaf or drawn out into a long fiber. (a) If 1.000 oz of gold, with a mass of 27.63 g, is pressed into a leaf of 1.000 um thickness, what is the area of the leaf? (b) If instead, the gold is drawn out into a cylindrical fiber of radius 2.500 um, What is the length of the fiber? (um = micro meters )

A person is on a diet might lose 2.3 kg per week. Express the mass loss rate in milligrams per second, as if the dieter could sense the second by second loss.

For about 10 years after the French Revolution, the French government attempted to base measures of time on multiples of ten: One week consisted of 10 days, one day consisted of 10 hour, one hour consisted of 100 minutes, and one minute consisted of 100 seconds. What are the ratio's of (a) the French decimal week to the standard week and (b) the French decimal second to the standard second ?

A top-gun pilot, practicing radar avoidance maneuvers, is manually flying horizontally at 1300 km/h. just 35 m above the level ground. Suddenly, the plane encounters terrain that slopes gently upward at 4.3 degrees, and amount difficult to detect visually. How much times does the pilot have to make a correction to avoid flying into the ground ?

Two Trains, each having a speed of 30 km/h are headed at each other on the same straight track. A bird that can fly 60 km/h flies off the front of one train when they are 60 km apart and heads directly for the other train. On reaching the other train it flies directly back to the first train, and so forth. What is the total distance the bird travels? (note: no reason is given why the bird is acting this way )

The position of a particle moving along the x axis is given in centimeters by x = 9.75 + 1.50 t^3 , where t is in seconds. Calculate (a) the average velocity during the time interval t= 2.00 s to t = 3.00 s ; (b) the instantaneous velocity at t = 2.00 s ; (c) the instantaneous velocity at t = 3.00 s; (d) the instantaneous velocity at t = 2.50 s; and (e) the instantaneous velocity when the particle is midway between its positions at t = 2.00 s and t = 3.00 s.

The position of a particle moving along the x axis depends on the time according to the equation x = ct^2 - bt^3, where x is in meters and t in seconds. (a) what units must c and b have ? Let their numerical values be 3.0 and 2.0, respectively. (b) At what time does the particle reach its maximum positive x position? From t = 0.0 s to t = 4.0 s, (c) what distance does the particle move and (d) what is its displacement? At t = 1.0, 2.0,3.0 and 4.0 s. what are (e) its velocities and (f) its accelerations ?

A jumbo jet must reach a speed of 360 km/h on the runway for takeoff. What is the least constant acceleration needed for take off from a 1.80m runway?

#### Solution Summary

Each solution is clearly explained with formulas solved.