Answer:
It is example of Closed system
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, 

2.) <span>Heat is transferred from your body into an ice cube by "Conduction"
3.) </span><span>The loudness of a sound will be determined by the wave’s "Frequency"
4.) </span>The speed of a sound wave <span>"is slower than an electromagnetic wave"
Hope this helps!
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Answer:
12N
Explanation:
when a force is applied to a body but still stays at rest or moves at a constant speed , the frictional force is equal to the force applied