If the earth is rotating at a high speed and we jump up, why doesn't the earth move below us at high speed?
Since other answers have correctly mentioned the atmosphere and such, let's take it out of the equation for the sake of argument and see what happens.In terms of the difference in the helicopter's path vs. the ground, let's look at what happens during one whole day as the Earth rotates. Assuming the helicopter can perform an ideal, vertical-acceleration-only hover, then the surface of the Earth and the helicopter have the same tangential speed as the Earth turns, due to conservation of momentum. But, since the helicopter is now a few feet (~1 meter) above the ground, the path the helicopter takes to go around the Earth during one day is now slightly longer as compared to the surface itself. The added circumference of that trip all the way around the Earth for the helicopter turns out be just 2 times Pi times the height above the ground. It takes the Earth just under 24 hours to rotate once on its axis, so the helicopter would have to move at an additional horizontal speed of maybe 18 feet (~5.5 meters) per 24 hours, or something like 0.00014 miles per hour (~0.00022 km/h) to stay directly over the same spot on the ground. This is such a negligible difference in horizontal speed that you don't notice it in any practical system.A real helicopter would deviate horizontally by a speed that is orders of magnitude more than that when it takes off anyway. And, of course, helicopters fly in the atmosphere, which is coupled to the ground. It's also fair to say that wind speed dominates any effects from conservation of momentum, as it's orders of magnitude larger, even at high altitudes. So, real aircraft worry about the difference in wind speed and direction vs. the ground, rather than orbital mechanics.
Hi! can anyone help me with these 3 math problems??
1. 2 cars leave the same place at the same time, but drive in opposite directions along a straight road. 1 car averages 55mi/h and the other 65mi/h. in how many hours will they be 250 miles apart? a. about 1.7 hours b. about 2.1 hours c. about 3.8 hours d. about 4.5 hours 2. helen rode her bike for 2 hours at a constant speed of 6km/h. she took the same route to come home but increased her speed by 6km/h. how far did she ride? a. 36km b. 24km c. 18km d. 4.5km 3. A helicopter leaves an airport and flies south 180mi/h. 30 minutes later, an airplane leaves the airport and follows the same route as the helicopter, only at a higher elevation. the airplane is flying 330mi/h. how many minutes will it take the airplane to catch up to the helicopter? a. 12 b. 24 c. 40 d. 48 ps: this is not my homework but a review for a midterm coming up. if u could explain how u got the answers it be great. thanks
If you jumped out of a plane at 10,000 feet, how long would it take to hit the ground?
It can vary based on body position and other factors...but let's assume you have a clean, stable exit into the relative wind at 10,000 feet, from a plane doing 80 knots forward speed with very little upper winds (this is typical in skydiving - although upper winds often vary). For he sake of simplicity, let's also assume that once you're at terminal velocity, you've adopted a neutral, belly-to-earth, arched body position. On exit, generally we say that the first 1000 feet takes about 11 seconds. This is longer than the remaining blocks of 1000 feet will take, due to vertical acceleration. Once you exit, you're still traveling forward - but that speed quickly bleeds off as your body picks up vertical speed and slows its forward speed due to drag. Once you've reached terminal velocity (120mph when flying in the neutral position I mentioned above), you generally fall about 5.5 seconds every 1000 feet. So - back of napkin calculations, you're looking at 11 seconds (1st 1000 feet) + 5.5 secs * 9 (the last 9k). Which gives you roughly 60.5 seconds from exiting a plane at 10k feet until meeting up with that big hunk of granite we call 'Earth.'