Search our library of Physics questions

Top answers

Physics

All levels

An exo-planet orbits its local star, of mass 2.00x10^30kg, in a steady circular orbit of radius 8.00x10^8km. Calculate the orbital period of the star, in years.

Key idea is equating gravitational force between planet and star (right hand side) with the centripetal force necessary to maintain the orbit (left hand side):(mv²)/r = (GMm)/r²

Answered by • Physics tutor

1632 Views

Discuss how the graph of orbital velocities in rotational galaxies against distance from the galactic centre implies the existence of dark matter.

Within the central swell of the galaxy, we can see that the orbital velocity increases almost linearly with distance, which corresponds with the formula for orbital velocity (namely that v=sqrt(GM/r)), as...

Answered by Jack T. • Physics tutor

1555 Views

What is the difference between Speed, Velocity and Acceleration?

Speed and Velocity are both measures of distance travelled in a given time and are therefore calculated using Speed=Distance/Time.Speed is a scalar quantity which means that it is quantified by a magnitud...

Answered by • Physics tutor

6967 Views

pressure = 2.3 × 10^5 Pa temperature= 200K. At a constant volume, when the temperature increases to 300K what is the pressure in Pa?

Divide pressure by temperature to get the constant = 1150. Making sure all values are in the correct units.Then multiply by 300K to get the increased pressure. 3.45 x 10^5 Pa

Answered by Rebecca P. • Physics tutor

1699 Views

What is the Rutherford alpha scattering experiment and what does it tell us?

The Rutherford experiment allowed us to experimentally disprove older models of the atom, forming the basis of the evidence for the nuclear model of the atom. The atom at the time was bel...

Answered by Aneesh J. • Physics tutor

7082 Views