A block m1 of mass 40 kg on a rough horizontal surface is connected to a ball m2 of mass 30 kg by a lightweight cord over a lightweight, frictionless pulley as shown. A force of magnitude 20 N at an angle, 40degrees, with the horizontal is applied to the block as shown, and the block slides to the right. The coefficient of kinetic friction between the block and surface is 0.4. Determine the magnitude of the acceleration of the two objects.

Answerthe energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.explanationwe define electric potential as the ratio electric potential energy to the charge,    then the following gives us the potential difference,      the formula  may be on your formula sheet.the change in electric potential energy would be the energy that would needed to move it from point a to point b. solving for that, we get    using q = 8.00  × 10⁻¹⁹ c and  δv = 2.00 v, we get    the energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.

F  you double the  force, you double the acceleration, but  if  you double the  mass, you velocity. all bodies accelerate at the  same  rate regardless of size or  mass.