i'm an A-level student
A balloon of total mass 1000 kg floats motionless in the air. If 100 kg of sand ballast are thrown overboard the baloon, with what acceleration does the balloon start to rise and what will be its velocity after 9 seconds?
Two objects of masses 2 kg and 3 kg are suspended by taut string passing over a frictionless pulley. Determine the acceleration of the two objects and the tension in the string when the system is released.
A man, using a 70 kg garden roller on a level surface, exerts a force on 200N at 30 degrees to the ground. Find the vertical force of the roller on the ground if he pulls; and if he pushes the roller.
A man tries to push a cargo along horizontal ground, but he finds that he cannot move it. If the force he exerted on the cargo is 800N, show the direction of the frictional force on the cargo and give its value.