Mass of each ball = 0.05 \(\text {kg}\)
Initial velocity of each ball = 6 \(\text m/\text s\)
Magnitude of the initial momentum of each ball, \(p_i\) \(=\) 0.3 \(\text {kg}\) \(\text m/\text s\)
After collision, the balls change their directions of motion without changing the magnitudes of their velocity.
Final momentum of each ball, \(p_f\) \(=\) –0.3 \(\text {kg}\) \(\text m/\text s\)
Impulse imparted to each ball = Change in the momentum of the system
\(=\) \(p_f-p_i\)
= – 0.3 – 0.3 = –0.6 \(\text {kg}\) \(\text m/\text s\)
The negative sign indicates that the impulses imparted to the balls are opposite in direction.
Figures 9.20(a) and (b) refer to the steady flow of a (non-viscous) liquid. Which of the two figures is incorrect ? Why ?
Newton’s 1st law states that a body at rest or uniform motion will continue to be at rest or uniform motion until and unless a net external force acts on it.
Newton’s 2nd law states that the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the object’s mass.
Mathematically, we express the second law of motion as follows:
Newton’s 3rd law states that there is an equal and opposite reaction for every action.