Answer:
(a) F = 239.575 N (b) t = 0.00649s or 6.49 ms
Explanation:
(a) By law of energy conservation, the bullet kinetic energy will be transferred to work done on stopping it from moving.
Formula for Kinetic Energy
where m is bullet mass, v is the velocity
Formula for work
where F is the average force and S is the distance travelled.



Substitute m = 4.2 g = 0.0042 kg, v = 370 m/s and S = 1.2 (m)

(b) If the force is constant, since the mass is constant and F = ma according to Newton's 2nd law, the acceleration on bullet is also constant

We also have 
At the time the bullet is coming to rest, 
Therefore, 

Answer:
it is because it do not produce smoke like fuel from wood.
Answer:
b. they can be observed and measured
Explanation:
Matter is anything that has weight and occupy space. There are three states of matter namely Solid, liquid and gas.
The properties of matter are both physical and chemical in nature. Both properties can be measured and observed. Phhysical properties are anything that can be measured without changing the state of the matter. Example of physical properties includes mass, volume, length, color etc.
Chemical properties is another properties of matter. This is the ability of the states of matters to combine with other substance to form a new product for example, rusting of iron, formation of salt etc.
All this as discussed are both measurable and can be observed.
Answer:
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Explanation:
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