Newton's Third Law in 1D
Newton's Third Law and Force Pairs
Do Now! Do these exercises immediately.
Not Now! Do these after you start to forget the topic, say in a week.
More! More exercises if you want. Maybe review before a test.
The video shows two masses, \(m_A = 40\) kg and \(m_B = 5\) kg. The ground is frictionless. There is a horizontal contact force (friction) on B by A providing an acceleration to the right of 4 m/s2. Mass A is accelerating to the right at 5 m/s2. What are the magnitudes of the frictional contact forces between the blocks and the tension in the string, T?
2. A 1000 kg car is pushing a 4000 kg truck down the road to the right. The truck is rolling freely in neutral and experiences a frictional contact force from the ground directed to the left with a magnitude of 800 N. The car is in gear and experiences a frictional contact force from the earth of 7500 N to the right. What are the accelerations of the two vehicles and contact forces between them?
Bob (90 kg) is standing on a box (60ks) that is on the floor of an elevator (800 kg). A cable is accelerating the elevator up with a tension of 13,000 N. What is the acceleration of the system and the forces between all three objects?