Systems of Particles & Linear Momentum
A constant force of 20 N is applied to an object for 2 seconds. What is the impulse on the object?
10 Ns
20 Ns
30 Ns
40 Ns
Under what conditions is linear momentum conserved in a system?
When external forces act on the system.
When internal forces act on the system.
When no external forces act on the system.
When the kinetic energy of the system increases.
A 2.0 kg block moving at 5.0 m/s on a frictionless surface collides with a 3.0 kg block at rest. After the collision, the 2.0 kg block moves at 1.0 m/s at an angle of 30 degrees relative to its original direction, and the 3.0 kg block moves at an angle of -45 degrees. What is the approximate speed of the 3.0 kg block?
1.5 m/s
2.8 m/s
3.2 m/s
4.1 m/s
A non-uniform rod of length has a linear mass density given by , where is a constant and is the distance from one end. Determine the x-coordinate of the center of mass.
What is impulse?
The energy of an object in motion.
The change in momentum of an object.
The force acting on an object.
The rate of change of velocity of an object.
A 2 kg object moving at 3 m/s collides head-on with a 1 kg object at rest. If the collision is perfectly inelastic, what is the final velocity of the combined mass?
1 m/s
2 m/s
3 m/s
4 m/s
What is the significance of the center of mass (COM) in analyzing the motion of a system of particles?
It is the point where the total kinetic energy of the system is concentrated.
It simplifies complex motion into a single point's movement, as if all the mass were concentrated there and all external forces were applied at that point.
It is the point where the gravitational potential energy of the system is minimized.
It represents the average velocity of all particles in the system.

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Two particles with masses and are located at positions and along the x-axis, respectively. What is the x-coordinate of the center of mass of this system?
4 m
5 m
6 m
8 m
A variable force is applied to an object. The force is described by the function , where is in Newtons and is in seconds. What is the impulse on the object from to seconds?
4 J
8 J
12 J
16 J