Two blocks of masses 5 kg and 10 kg are in contact on a smooth horizontal surface. A horizontal force of magnitude 15 N pushes them from left to right (a) Find the magnitude of the acceleration of the system,

Two blocks of masses 5 kg and 10 kg are in contact on a smooth horizontal surface. A horizontal force of magnitude 15 N pushes them from left to right (a) Find the magnitude of the acceleration of the system, (b) Find the magnitude of the reaction force between the blocks.
A block moves up an incline of angle 25° under the action of the three forces. One force of 40 N is applied horizontally, another force of 20N is applied parallel to the incline and the last force of 15 N is applied perpendicular to the incline. Find the work done by each force as the block moves a distance of
2m up the incline.
A small ball of mass m is attached to a massless thread that is fixed to the roof of a car. (a) Find the angle does the thread make with the vertical when the car has a constant acceleration of 5 m/s2. (b) What is the angle when the car is moving at constant velocity of magnitude v = 50 km/h?