System shown in figure is in equilibrium and at rest. The spring and string are massless, now the string is cut. The acceleration of mass 2m and m just afterthe string is cut will be
- g/2 upwards, g downwards
- g upwards, g/2 downwards
- g upwards, g downwards
- 2g upwards, g downwards
The Correct Option is A
Solution and Explanation
$\hspace15mm T = mg \hspace15mm$
Now, the string is cut. Therefore, T = mg force is decreased on mass m upwards and downwards on mass 2m
$\therefore \hspace15mm a_m=\frac{mg}{m}=g\, \, \, \, \, \, \, \, \, \, $(downwards) and
$\hspace15mm a_{2m}=\frac{mg}{2m}=\frac{g}{2} \hspace15mm (upwards)$
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Concepts Used:
Momentum
It can be defined as "mass in motion." All objects have mass; so if an object is moving, then it is called as momentum.
the momentum of an object is the product of mass of the object and the velocity of the object.
Momentum = mass • velocity
The above equation can be rewritten as
p = m • v
where m is the mass and v is the velocity.
Momentum is a vector quantity and the direction of the of the vector is the same as the direction that an object.