Yr2 Phyics

Gravitational potential at a point is....

• the work done in bringing a unit mass from infinity to the point
• the work done in bringing a unit mass from the point to infinity
• the work done in bringing a unit charge from infinity to the point
• the work done in bringing a unit mass from twice the radius of the mass to the point

Tags

NGSS.HS-PS2-4

The area under a Force-distance graph is....

• the energy lost by the mass
• the work done on a mass
• the charge on a mass
• the potential difference of a mass

An object is moved from A to B in the gravitational field of Earth. The distance between the centre of Earth and B is twice that of A. If the gravitational potential energy of the object at A is –2.0 MJ, what is the gravitational potential energy of the object at B?

• zero
• -0.5MJ
• -1.0MJ
• -4.0MJ

A satellite of mass m is in a circular orbit of radius R around Earth. The time required to complete one revolution is T. What would be the kinetic energy of the satellite?

• GMm/R
• GMm/2R
• mR/T
• 2m(R/T)²

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-1

The Earth may be assumed to be spherical with radius r and density p.

Which equation correctly relates the gravitational field strength g at its surface to these quantities and

the gravitational constant G?

• g=G/ r²

• g=3 G \ 4 π r p

• g= G 4 π r p \ 3

• g= G 4 π r² p \ 3

The gravitational field strength outside a uniform sphere of mass Mis the same as that of a point mass Mat the centre of the sphere. The Earth, which may be assumed to be spherical and of radius r, has a gravitational field strength g at its surface. Which expression gives the gravitational field strength at height h above the ground?

• g r² / (r + h)²

• g r / r + h

• g (r- h) / r

• g (r-h)² / r²

Consider a parallel plate system with the top plate being positive and the bottom negative. If I move a positive charge parallel to the top plate what happens to the energy of the charge?

• No effect
• E_k increases while E_p decreases
• E_k decreases while E_p increases
• Impossible to tell

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-5

What is the magnitude of the force between the two charged spheres shown? (Hint: You do not need to convert the units.)

• 1.6

• 1.4

• 1.2

• 1.0

An electron has charge –e and mass m_e. A proton has charge e and mass 1840m_e. A "proton volt" is equal to:

• 1eV 
• 1840eV
• (1/1840)eV
•  sqrt(1840)eV

A tiny sphere carrying a charge of 6.5 µC sits in an electric field, at a point where the electric potential is 240 V. What is the sphere’s potential energy?

• 2.7 x 10^-8 J 
• 6.5 x 10^-6 J 
• 1.6 x 10^-3 J
• 240 J 

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-5