Answer:
The fractional kinetic energy will be lost if the collision is inelastic. In inelastic collision, the kinetic energy is converted into other forms of energy.
The lost energy became heat and sound energy.
Explanation:
During inelastic collision, the kinetic energy of a moving object does not conserve. It changes into another form of energy such as sound energy and heat energy etc.
For example, when a moving car hit another car or wall etc, the kinetic energy is converted into sound and heat energy. This type of collision is inelastic collision.
By looking at the acceleration of the object.
In fact, Netwon's second law states that the resultant of the forces acting on an object is equal to the product between the mass m of the object and its acceleration:

So, when static friction is acting on the object, if the object is still not moving we know that all the forces are balanced: in fact, since the object is stationary, its acceleration is zero, and so the resultant of the forces (left term in the formula) must be zero as well (i.e. the forces are balanced).
All of those! A qualitative observation is any one that doesn't include numbers. <em>Quantitative </em>observations include numbers, but not usually any other kind of information.
Answer:
B. A rubber band is stretched out
Explanation:
Length of the pendulum (l) = 2 m
Acceleration due to gravity = g = 9.8 m/s^2
For small amplitude, the pendulum will undergo simple harmonic motion.
Hence, the time period of the pendulum for small amplitude = 
Now, plug the values of l and g
T = 
T = 2 × 3.14 × 0.451
T = 2.83 seconds
Hence, the time period of the pendulum for small amplitude = 2.83 s