All masses exert equal and opposite gravitational forces on each other.
Any object released on Earth will fall vertically downwards towards the centre of the Earth, provided there are no other forces acting on it apart from the force of gravity.
The object is said to be in free fall and the acceleration of free fall is equal to g (9.81 ms-2).
g is the acceleration due to gravity and is also equal to the gravitational field strength.
The value of g depends on altitude but it is usually considered to be 9.81ms-2. The value of g can be determined in the lab using the following apparatus.
An electromagnet holds a small steel ball a measured height s above a trapdoor.
When the current is switched off a timer is triggered and the electromagnet demagnetises. The steel ball falls and breaks the contact when it hits the trap door, so the timer stops.
The equation s = ut + ½gt2 can be used to determine g since u = 0 and therefore ut = 0
Any object released on Earth will fall vertically downwards towards the centre of the Earth, provided there are no other forces acting on it apart from the force of gravity.
The object is said to be in free fall and the acceleration of free fall is equal to g (9.81 ms-2).
g is the acceleration due to gravity and is also equal to the gravitational field strength.
The value of g depends on altitude but it is usually considered to be 9.81ms-2. The value of g can be determined in the lab using the following apparatus.
An electromagnet holds a small steel ball a measured height s above a trapdoor.
When the current is switched off a timer is triggered and the electromagnet demagnetises. The steel ball falls and breaks the contact when it hits the trap door, so the timer stops.
The equation s = ut + ½gt2 can be used to determine g since u = 0 and therefore ut = 0