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CBSE Class 9 Answered

A frictionless wagon is pushed, from rest, with a force of 60N for 14 seconds. If it then strikes a wall and comes to rest in 0.15 seconds, how much average force does the wall exert on the wall.   GIVE WITH PROPER STEPS.  
Asked by acv27joy | 06 May, 2018, 08:21: PM
answered-by-expert Expert Answer
The change in velocity takes place due to the force applied for given time. This is called impulse.
 
The wagon is set in motion by impulse P1 = 60×14=840
The wagon is brought to rest by impulse P2 = F × 0.15
 
The impulse that set the wagon in motion must be equal to impulse that put wagon to rest 
Thus,  P1 =  P2 
→ 840= F × 0.15
→ F= 840/0.15
Thus F = 5600 N
Answered by Shiwani Sawant | 07 May, 2018, 10:12: AM

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