Pick an appropriate option to justify the given statement: _____ is a showcase of a model of an atom which is bound to fail. [Rutherford’s model, Thomson’s model]
Answer
Rutherford’s model Description: Due to the presence of the force attraction between electron and the nucleus, the atom always remain slightly unstable, and doomed to collapse.
A force of \(4.9\ N\) is required to slide a body of mass \(5\ kg\) on a rough horizontal surface with a constant speed. What is the value of coefficent of friction?
Pick an appropriate option to justify the given statement: Mass distribution is uniform in __________ but highly irregular in ___________ . \([\)Rutherford’s model, Thomson’s model, both the models\(]\)
A \(70\ kg\) man stands in contact against the inner wall of a hollow cylindrical drum of radius \(3\ m\) rotating about its vertical axis with \(200\ rev/min\). The coefficient of friction between the wall and his clothing is \(0.15\) . What is the minimum rotational speed of the cylinder to enable the man to remain stuck to the wall(without falling) when the floor is suddenly removed ?
The standard Gibbs energy for the given cell reaction in \(kJ\)\(mol^{-1}\) at \(298\)\(K\) is \(Zn(s)+Cu^{2+}(aq)\to Zn^{2+}(aq)+Cu(s)\) \(E^{\circ }\) =\(2V\) at \( 298\)\(K\) (Faraday’s constant, \(F=96000\ C\)\(mol^{-1}\))( )
The sum of the surface areas of cuboid with sides \(x\), \(2x\) and \(\frac {x}{3}\) and a sphere is given to be constant. Prove that the sum of their volumes is minimum if \(x=3\times\) radius of the sphere. Also find the minimum value of the sum of their volumes.