3. A block of mass m = 2.00 kg rests on the left edge of a block of mass M = 8.00 kg. The coefficient of kinetic friction between the two blocks is 0.300, and the surface on which the 8.00 kg block rests is frictionless. A constant horizontal force of magnitude F = 10.0N is applied to the 2.00-kg block, setting it in motion as shown in Figure. The distance L that the leading edge of the smaller block travels on the larger block is 3.00 m. L M F> m M (a) Draw a separate free-body diagram for each block. (b) In what time interval will the smaller block make it to the right side of the 8.00-kg block? as (Note: Both blocks are set into motion when the force is applied.) (c) How far does the 8.00-kg block move in the process?

A 4.6-kg block is pushed 2.3 m up a vertical wall with constant speed by a constant force of magnitude F applied at an angle of  ? = 30°  with the horizontal, as shown in the figure below. If the coefficient of kinetic friction between block and wall is 0.30, determine the following. A figure, drawn from a side view, shows the right side of a rectangular block pushed up against a rough, vertical wall. A force vector F acts on the block and is represented by a diagonal rrow pointing up and to the right, toward the center of the block's left side. The arrow forms an angle ? with the horizontal. (a) the work done by  F  J(b) the work done by the force of gravity J(c) the work done by the normal force between block and wall J(d) By how much does the gravitational potential energy increase during the block's motion? J

Q2: The mass center of the rear-engine 1500- kg car is at G. Determine the normal forces NA and Ng exerted by the road on the front and rear pairs of tires for the conditions of (a) being stationary and (b) braking from a forward velocity v with all wheels locked. The coefficient of kinetic friction is 0.90 at all tire/road interfaces. Ans.: (a) NA= (b) NA = 5886 N, NB = 8775N, NB = 8829 N 5940 N 600 mm B 1650 mm 1100 mm

A 2.2-kg sphere S is being moved in a vertical plane by a robotic arm. When the angle is 36°, the angular velocity of the arm about a horizontal axis through O is 45 deg/s clockwise and its angular acceleration is 176 deg/s² counterclockwise. In addition, the hydraulic element is being shortened at the constant rate of 550 mm/s. Determine the necessary minimum gripping force P if the coefficient of static friction between the sphere and the gripping surfaces is 0.58. Compare P with the minimum gripping force P, required to hold the sphere in static equilibrium in the 36° position. 1.0 m $ Answers: P= Ps= i i N N