Answer:
no not always sometimes they react at all so false I hope I helped :)
Answer:
Explanation:
Given
mass of steel ball 
initial speed of ball 
Final speed of ball
(in upward direction)
Impulse imparted is given by change in the momentum of object
therefore impulse J is given by




so magnitude of Impulse =4 N-s
Answer:
2.75 meters.
Explanation:
1 meter = 100 centimeters.
There are 275 centimeters.
275/100=2.75
So, each piece of wallpaper was 2.75 meters long.
Answer:
(a) 
(b) 15 hours
Explanation:
half life, T = 12 hours
No = 19 g
(a) Let N be the amount remaining after time t.
Let λ be the decay constant.

The equation of radioactivity used here is given by


(b) N = 8 gram
Substitute the values in above equation

λ = 0.0577 per hour
So, 

Take natural log on both the sides
- 0.0577 t = - 0.865
t = 15 hours
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