g (N/kg) - Quantum Tunneling
Transcript g (N/kg) - Quantum Tunneling
The gravitational field strength is the amount
of force acting on each kilogram of mass.
It is measured in N/Kg.
It is not the same everywhere.
The gravitational field strength is a vector
quantity whose direction is always toward the
center of the earth.
As the gravitational field strength and the
acceleration due to gravity are numerically
equal, the same symbol, g, is used for both.
g = 9.8 N/kg, or g = 9.8 m/s2
9.8 N/kg is an average for the earth’s surface
Distance to centre
90 (north pole)
The force of
between any two
objects is directly
proportional to the
product of the masses
of the objects, and
to the square of the
distance between their
G (N.m2/kg2 )
where G is a constant
G = 6.67 x 10-11 N.m2/kg2
Used to determine the Universal Gravitational
What causes the Ocean tides?
How do scientists decide where satellites
should orbit Earth?
Copy and complete the following chart.
Assume that the same object is used on each
of the three planets.
2 ) The force of gravity on an astronaut us 600
N at the Earth’s surface. What is the force of
gravity on him at each of the following
distances from the centre of the Earth,
measured in multiples of the Earth’s radius?
3 ) Two of the largest oil tankers in the world,
the Batilus and the Bellaya, have masses of
492 000 t, fully loaded. If they were moored
side by side, 1.0 m apart, their centres would
be 64m apart. Calculate the force of gravity
4 ) Sirius B is a white dwarf star, in orbit around
Sirius, with a mass of 2.0x 1030 kg, and a
radius of 2.4x107 m.
(a) What is the force on a 1.0 kg mass on the surface
of Sirius B?
(b) What is the acceleration due to gravity on the
surface of Sirius B?
Static and Kinetic Friction force on Wednesday
Quiz on Friday....