1) The position of an object is given by the expression below (units are meters and seconds). Find the speed and acceleration of the object at time t = 7.50 s. x ( t ) = 10 + 7t + 5t" + 2t" 2) Two blocks are stacked and pushed along a frictionless table surface. There is a static coefficient of friction of 0.455 between the two blocks. What is the maximum force F that can be applied to the lower block (as shown in the diagram) such that the upper block does not slide. 16 kg F 18 kg 3) A motor is used to pull a 400 kg crate a distance of 14.0 m upward along a 13.0 degree incline. The crate and incline surfaces have a coefficient of kinetic friction of 0.450, and the crate is pulled along at a constant speed of 1.10 m/s. Find the power of the motor. |