Two blocks A and B with mA = 1.1 kg and mB = 0.88 kg are connected by a string of negligible mass. They rest on a frictionless horizontal surface. You pull on block A with a horizontal force of 6.7 N.

In Figure (a), a constant horizontal force F is applied to block A, which pushes against block B with a 21.0 N force directed horizontally to the right. In Figure (b), the same force is applied to block B; now block A pushes on block B with a 13.0 N force directed horizontally to the left. The blocks have a combined mass of 12.0 kg. What are the magnitudes of (a) their acceleration in Figure (a) and (b) force F. ? (a) Number i (b) Number i A B (a) Units Units BA (b)

A block is pressed against a vertical wall by a force F, as the drawing shows. This force can either push the block upward at a constant velocity or allow it to slide downward at a constant velocity. The magnitude of the force is different in the two cases, while the directional angle is the same. Kinetic friction exists between the block and the wall, and the coefficient of kinetic friction is 0.260. The weight of the block is 47.0 N, and the directional angle for the force F is 0 = 48.0°. Determine the magnitude of F when the block slides (a) up the wall and (b) down the wall. (a) P = (b) P= i i P >

Question 16, Physics - equation sheet attached

A car of mass m₁ 1000 kg is connected to a trailer of mass m2 = 400 kg by a taut inextensible cable. The car's engine provides a constant forward driving force Fx = 7000 N, which causes the car-plus-trailer to accelerate forwards along the horizontal x-axis. The tension of the cable produces a force on the trailer and also a force on the car. You may assume that the magnitude of the two forces is the same. You may also ignore friction. What is the tension in the cable joining the car to the trailer? Give your answer by entering a number, correct to an appropriate number of significant figures, in the empty box below.

A 2.5 kg block is initially at rest on a horizontal surface. A horizontal force F of magnitude 6.2 N and a vertical force P are then applied to the block. The coefficients of friction for the block and surface are us = 0.38 and uk = 0.22. (a) Determine the magnitude of the frictional force acting on the block if the magnitude of P is 8.0 N. (b) Determine the magnitude of the frictional force acting on the block if the magnitude of P is 10.0 N. (c) Determine the magnitude of the frictional force acting on the block if the magnitude of P is 12.0 N.

In a two-dimensional tug-of-war, Alex, Betty, and Charles pull horizontally on an automobile tire at the angles shown in the picture. The tire remains stationary in spite of the three pulls. Alex pulls with force É A of magnitude 222 N, and Charles pulls with force magnitude 188 N. Note that the direction of F c is not given. What is the magnitude of Betty's force F B if Charles pulls in (a) the c of direction drawn in the picture or (b) the other possible direction for equilibrium? Alex Charles 140° Betty (a) Number i Units (b) Number i Units