Oquizy

An elevator of mass 800 kg is connected over a frictionless pulley to a counterweight of mass 600 kg. The system is released from rest. Taking g = 10 m/s², what is the tension in the cable?

6400 N 6860 N 7200 N 7600 N

A skydiver of mass 75 kg first falls freely without a parachute, then opens the parachute. Before the parachute opens, the skydiver’s terminal velocity is 60 m/s. After the parachute opens, the new terminal velocity is reduced to 15 m/s. Which statement best explains this change?

The gravitational field strength decreases with height. The parachute increases air resistance, reducing the speed needed to balance weight. The skydiver’s mass decreases, reducing weight. The skydiver’s weight increases, so terminal velocity is lower.

What is meant by inertia?

The ability to gain speed quickly The acceleration due to gravity The force keeping objects at rest The property that resists changes in motion

A 15 kg box is pushed across a horizontal floor with a constant acceleration of 2.0 m/s². If the force of friction acting on the box is 10 N, what is the magnitude of the force being applied to the box?

20 N 30 N 40 N 50 N

Which of the following is a contact force?

Electrostatic force Friction Gravitational force Magnetic force

A train consists of an engine of mass 5000 kg pulling two cars of masses 2000 kg and 3000 kg in a straight line on a horizontal track. The train accelerates at 2 m/s². What is the tension in the coupling between the two cars behind the engine?

2000 N 4000 N 6000 N 8000 N

Quiz: Physics - Dynamics