A force parallel to the x-axis acts on a particle moving along the x-axis. This force produces potential energy U (x) given by U (x)=αx4,where α = 0.750 J/m4J/m4. # What is the magnitude of the force when the particle is at x = -0.800 m? Express your answer with the appropriate units.
A book rest on a table which it's face having a sides 30cm by 25cm . if it exerts apressure of 200pa then determine the mass of the block.