Calculating Stopping Force for a 850kg Car at 110km/h | Physics Question

  • Thread starter Thread starter physicsgrade11
  • Start date Start date
AI Thread Summary
To calculate the stopping force for an 850kg car traveling at 110km/h and brought to rest in 10 seconds, one can apply the impulse-momentum principle or kinematics. The average force can be determined using the formula F_avg * Δt = m * Δv, where Δv is the change in velocity. The discussion clarifies that the question specifically seeks the force required to stop the car, rather than external forces like friction or wind. Understanding impulse and momentum is crucial, but kinematics can also be used to find the necessary acceleration and subsequently the stopping force. The emphasis is on determining the magnitude of the constant force needed to achieve this stop within the given timeframe.
physicsgrade11
Messages
9
Reaction score
0
ok here is the question exaclty- its worth 5 marks so i don't know what I am 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?
 
Physics news on Phys.org
F_{avg}\Delta t = m\delta v
 
Looks like an impulse question.
 
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.
 
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.
 
Good point...I guess they should have said "determine the magnitude of the constant force that brings the car to a stop".
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Correct statement about a reservoir with an outlet pipe'
The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
Back
Top