A 10 kg block is placed on a horizontal surface whose coefficient of friction is 0.25. A horizontal force P = 15 N first acts on it in the eastward direction. Later, in addition to P a second horizontal force Q = 20 N acts on it in the northward direction : (Both east and west are in the plane of the fig and the gravity acts perpendicular to this plane )The block will not move when only P acts, but will be about to move when both P and Q actIf the block moves, the acceleration will be 0.5 m/s2.When the block moves, its direction of motion will be   (4/3) east of north When both P and Q act, the direction of the force of friction acting on the block will be   (3/4) west of      south

`A 40 kg slab rests on a frictionless floor. A 10 kg block rests on top of the slab. The static coefficient of friction between the block and the slab is 0.60 while the kinetic coefficient is 0.40. The 10 kg block is acted upon by a horizontal force of 100 N. If g = 9.8 m/s2 the resulting acceleration of the slab will be  A.0.98 m/s2B.1.47 m/s2  C.1.52 m/s2D.6.1 m/s2

A block of mass 1 kg is pushed up a surface inclined to horizontal at an angle of 60∘ by a force of 10 N parallel to the inclined surface as shown in figure. When the block is pushed up by 10 m along inclined surface, the work done against frictional force is : [g=10 m/s2]

A 2.8 kg block is pushed along a horizontal floor by a force F of magnitude 19 N at an angle 𝜃 = 35° with the horizontal (Fig. 6-49). The coefficient of kinetic friction between the block and floor is 0.25. (The block initially starts at rest.)Figure 6-49(a) Calculate the magnitude of the frictional force on the block from the floor. N(b) Calculate the magnitude of the acceleration of the block. m/s2

friction force acting on the block

A 6.9-kg block is held in place against the spring by a 69-N horizontal external force. The external force is removed, and the block is projected with a velocity v1 = 2.2 m/s upon separation from the spring. The block descends a ramp and has a velocity v2 = 3.5 m/s at the bottom.The track is frictionless between points A and B. The block enters a rough section at B, extending to E.  The coefficient of kinetic friction is 0.39. The velocity of the block is v3 = 1.8 m/s at C. The block moves on to D, where it stops.What is the spring constant of the spring?Express your answer in N/m, to at least one digit after the decimal point.