Astronauts on the ISS orbit Earth 16 times a day at a height of 400km above the surface. Given that the radius of Earth is approximately 6400km, how fast are the astronauts travelling?
v = 2𝜋R/T where R is the orbital radius, T is the time period.R = radius_of_earth + height_of_orbit = 6800km + 400km = 6800km = 6.8×106m.T = hours_in_day/number_of_orbits_in_day = 24/16 hours = 1.5 hours = 90 minutes = 5400 seconds.v = (2𝜋×6.8×106)/5400 ≈ 7900ms-1.For appreciation of how fast this is, this corresponds to around 18000mph, which is 10 times the speed of an average bullet, and over 20 times the speed of sound in air!
PV
Related Physics GCSE answers
All answers ▸A bowling ball is thrown into the alley, having velocity of 3 ms^-1 at the start of the bowling alley. It decelerates at a constant rate, before hitting the skittles at 2 ms^-1 after 4 s A) calculate the acceleration of the ball.
Explain the difference between current and voltage
On a see-saw Mary, weight 600N balances John, weight 200N when she sits 1.5m away from the pivot. How far from the pivot is John?
What are the differences between microwaves and radio waves? How does this effect what we use them for?