Momentum = mass x velocity
Before collision
Momentum 1 = 2 kg x 20 m /s = 40 kg x m/s
Momentum 2 = 3 kg x -10m/s = -30 kg x m/s
After collision
Momentum 1 = 2 kg x -5 m/s = -10 m/s
Momentum 2 = 3 kg x V2 = 3V2
Total momentum before = total momentum after
40 + -30 = -10 + 3V2
V2 = <span>6.67 m/s
Total kinetic energy before
</span><span>= (1/2) [ 2 kg * 20 m/s * 2 + 3 kg * ( -10 m/s) *2 ]
= 550 J
</span>
<span>Total kinetic energy after
</span>= (1/2) [ 2 kg * ( - 5 m/s) * 2 + 3 kg * 6.67 m/s *2 ]
= 91.73 J
Total kinetic energy lost during collision
=<span>550 J - 91.73 J
= 458.27 J</span>
Answer:15.8 m/s
Explanation:
Given
Gravitational Force 
Air resistance 
mass of Parachutist 
Velocity after 



Now Parachutist opens the parachute
Net for on Parachutist

drag force
therefore deceleration 
velocity after 10 s is



Number 4 is : a light hour is a measure of time in space used to calculate the length of time between one object to another and one light hour equals 1.079 × 109 kilometers or 1.079e+9
For the writer, scientific models are paradigms of set of patterns that is assumed to happen in a particular situation or circumstance which is why it was created and modeled, to explain a certain phenomenon. Take for instance the biogeochemical cycle model –water cycle. The water cycle model involves the different process which was observed happen as the current cycle has been experimented and predicted to happen again with the same process. <span>
</span>Models can represent things that are too small to see. <span> Scientists rely on models to represent concepts and processes in physical science because models can represent things that are too small to see. In fact, they are actually used to give a better perspective of what is occurring on these hidden to the naked eye matters –which may include atoms, cells, and entities unseen and latent. It gives scientists the ideas and structure, restructure, integrate and ponder on new hypothesis on these matters. <span> </span></span>
Answer:
V=15.3 m/s
Explanation:
To solve this problem, we have to use the energy conservation theorem:

the elastic potencial energy is given by:

The work is defined as:

this work is negative because is opposite to the movement.
The gravitational potencial energy at 2.5 m aboves is given by:

the gravitational potential energy at the ground and the kinetic energy at the begining are 0.
