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Physics
GCSE

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 =...

Answered by Paaryn V. Physics tutor
1754 Views

What are the different kinds of nuclear radiation?

There are three kinds of nuclear radiation that you need to know for GCSE physics, and each is considerably different from the others. Firstly, alpha radiation: this is when a chunk of the nucleus is emit...

Answered by Matthew M. Physics tutor
1694 Views

Describe the forces acting on a skydiver jumping out of a plane and explain why opening a parachute reduces the velocity

Initially the air resistance (r) is low, and the force due to gravity (mg) is high. These forces are unbalanced so the skydiver accelerates downwards. (mg > r)As the velocity increases the force of air...

Answered by Fred J. Physics tutor
3965 Views

Describe the different forces upon a falling object with reference to Newton's first law.

A falling object will reach terminal velocity when the force draging it down (ie its weight due to gravity) is equal to the air resistance opposing the motion upwards. When the two forces are equal the ob...

Answered by Adam L. Physics tutor
2031 Views

Why do we say that objects moving in a circle have acceleration even if their speed remains constant?

Because their speed might remain constant, but their velocity doesn't. Remember, velocity is a vector, so it has magnitude (which is the speed of the object), but also direction. For an object moving in a...

Answered by Boris A. Physics tutor
1799 Views

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