Kepler's second law implies that the closer a planet is to its star, the faster the planet travels. This law is related to conservation of angular momentum. The law is important because the planets' orbits around stars are not circular, so planets are closer to their stars at certain points.Know More
Kepler's second law assumes that if a line is drawn between a star and its planet, for any set time period, that line sweeps out the same area each period, no matter where in orbit the planet is at the time.
For example, if the time period is 10 days, the line between the planet and the star sweeps out equal areas every 10 days. This is possible because when the planet is closer to its star, it moves faster, and when it is further away from its star, it moves slower. At aphelion, the point in a planet's orbit furthest away from the star, the planet moves the slowest. At perihelion, the planet is closest to its star and moves the fastest. This is because of the planet's conservation of angular momentum.
Angular momentum is directly proportional to an object's moment of inertia and angular velocity. When a planet's distance from its star increases, its moment of inertia increases. For its angular momentum to remain the same, the planet's angular velocity has to decrease.Learn more about Motion & Mechanics
The compressional speed for steel is approximately 19,700 feet per second, while the shear speed is approximately 10,600 feet per second. Acoustic waves propagate in steel at two different speeds: longitudinal, or compressional wave velocity and transverse, or shear wave velocity. However, these approximate values may significantly differ from the actual speed due to several factors, including fiber or grain alignment, composition, temperature or permeability.Full Answer >
The terminal velocity of a skydiver in freefall is approximately 50 to 60 miles per second or roughly 125 to 135 mph. While the term has been popularized by skydiving enthusiasts, however, the concept of terminal velocity is applicable to the study of physics in general.Full Answer >
A 1-inch PVC pipe handles 58 gallons of water a minute at a peak velocity flow of about 18 feet per second. This is equivalent to 3,510 gallons per hour.Full Answer >
A 50 pound-mass dumbbell is pulled downward by the Earth's gravitational field at an acceleration of 32.174 feet-pound-mass per second squared, so the force to lift it is 1,608.7 pounds-force. Newton's second law of motion states that force is equal to mass multiplied by acceleration, gravitational or otherwise.Full Answer >