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Poorly worded question

  • #1
ok here is the question exaclty- its worth 5 marks so i dont know what im missing..

A car with a mass of 850kg is moving in a straight line at a constant speed of 110km/h. It is brought to rest in 10.0s. What constant force is acting to stop the car?
 

Answers and Replies

  • #2
148
0
[tex]F_{avg}\Delta t = m\delta v[/tex]
 
  • #3
298
0
Looks like an impulse question.
 
  • #4
Thanks anyways guys but i got it. I think i was thinking it was asking what force as in friction or wind etc. was stopping it but its asking the force it would take to stop it in that time.
 
  • #5
Doc Al
Mentor
44,870
1,119
If you are not familiar with impulse/momentum, you can always use kinematics to find the acceleration, then apply Newton's 2nd law to find the force.
 
  • #6
cepheid
Staff Emeritus
Science Advisor
Gold Member
5,192
35
Good point...I guess they should have said "determine the magnitude of the constant force that brings the car to a stop".
 

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