Answer:
Option (b) is correct.
Explanation:
Elastic collision is defined as a collision where the kinetic energy of the system remains same. Both linear momentum and kinetic energy are conserved in case of an elastic collision.
Inelastic collision is defined as a collision where kinetic energy of the system is not conserved whereas the linear momentum is conserved. This loss of kinetic energy may due to the conversion to thermal energy or sound energy or may be due to the deformation of the materials colliding with each other.
As given in the problem, before the collision, total momentum of the system is
and the kinetic energy is
. After the collision, the total momentum of the system is
, but the kinetic energy is reduced to
. So some amount of kinetic energy is lost during the collision.
Therefor the situation describes an inelastic collision (and it could NOT be elastic).
Answer:
C = 1.01
Explanation:
Given that,
Mass, m = 75 kg
The terminal velocity of the mass, 
Area of cross section, 
We need to find the drag coefficient. At terminal velocity, the weight is balanced by the drag on the object. So,
R = W
or

Where
is the density of air = 1.225 kg/m³
C is drag coefficient
So,

So, the drag coefficient is 1.01.
Answer: The fundamental frequency of the slinky = 8Hz
An input frequency of 28 Hz will not create a standing wave
Explanation:
Let Fo = fundamental frequency
At third harmonic,
F = 3Fo
If F = 24Hz
24 = 3Fo
Fo = 24/3 = 8Hz
If an input frequency = 28 Hz at 3rd harmonic
Let find the fundamental frequency
28 = 3Fo
Fo = 28/3
Fo = 9.33333Hz
Since Fo isn't a whole number, it can't create a standing wave