A show, a horizontal force F is pushing a 1.4 kg block up a frictionless 14° incline from point A to point B which are 1.2 m apart. The work exerted by F on the block is 5 J. If the kinetic energy at point B is 4 J, the kinetic energy (in J) at point A is:

From rest, a 2.3 kg block slides down a frictionless hill and then across a rough patch that has a coefficient of kinetic friction of 0.64. As shown, the velocity of the block after crossing the rough patch is 3.5 m/s directed to the left. What is the vertical height of the hill, h (in m)?

A square of side L is free to rotate about the point P – at the middle of the lower side – as shown in the figure. All five forces acting on the square have the same magnitude. Rank the five torques, τ, produced by those forces, from the greatest to the smallest.

A massive crane (assume it is fixed to the Earth) is lifting a mass of 7600 kg. The arm of
the crane is supported at its base at point B by a strong pivot and at its top at point A by a cable. The
arm makes an angle with the horizontal of 40 and the cable makes an angle 30 with the horizontal as
well. The arm is 12.0 m long. The mass is lifted from a point on the arm 0.52 m from the end point A.
Assume that the mass of the arm is small enough to ignore, find the tension in the cable

The schematic diagram for a hydraulic lift shows two pistons in a container filled with a fluid ( of density of (750 kg/m^3 ). The larger piston on the right has a diameter of 13 cm and a mass of 3.6 kg , while the piston on the left has a diameter of 5.1 cm and a mass of 2.3 kg. The height difference h (in m) between the two pistons is: