Question
Question: One newton is the force by which a mass of \(1000\;g\) is attracted towards earth. True or False. ...
One newton is the force by which a mass of 1000g is attracted towards earth. True or False.
A. True
B. False
Solution
We know that newton is the SI unit of force. Hence we can define one newton the same way we define force on any given object. Then we can compare the definition and the statement to state if the given statement is true or false.
Formula: 1N=1kg×1m/s2
Complete answer:
We know that force is an interaction between two objects which causes inertia, which is to say that it changes the state of the motion. We also know that an external force, being a vector, can change the direction or the speed of the moving object. We also know that external force is required to do work.
However, the most simple and basic definition of force is given from Newton's second law motion which states that, the net force acting on a given body is the rate of change of momentum P of the given body with time.
F=dtdP=dtd(mv), where m and v is the mass and the velocity of the given object with respect to time t
It the mass remains constant with time, and then we can say that,
F=mdtdv
Clearly, since v is a function of time, also we know that, dtdv=a, where a is the acceleration of the given body.
We get, F=ma
Thus, we can also define force as the acceleration needed to accelerate a given mass.
Then on the same basis, we can say that, to accelerate a mass of 1kg=1000g at a rate of 1m/s2, we need to exert a force of 1N.
1N=1kg×1m/s2
Hence we can say that the given statement is false.
Note:
Thus clearly, 1N is not necessarily, the force between the object and the gravitation. As the acceleration due to gravity is g=9.8m/s2 and not 1m/s2. Also, the pull experienced by a given mass towards the earth is called weight W=mg, and is given from Newton's law of Gravitation.