Need find end velocity given accel., time, distance

  • Thread starter Thread starter LVanderlinden
  • Start date Start date
  • Tags Tags
    Time Velocity
Click For Summary
SUMMARY

The discussion focuses on calculating the final velocity of a car that decelerates with a constant acceleration of -5.90 m/s² over a time period of 4.45 seconds, covering a distance of 60.0 meters. The user initially attempted to find the initial velocity (Vo) using the incorrect formula Vo = x - (at²/2) and subsequently calculated the final velocity (Vf) as 13.4 m/s, which was incorrect. The correct approach involves using the equations of motion to accurately determine the initial velocity and subsequently the final velocity upon impact with the tree.

PREREQUISITES
  • Understanding of kinematic equations of motion
  • Familiarity with concepts of acceleration and deceleration
  • Basic algebra skills for solving equations
  • Knowledge of units of measurement in physics (meters, seconds)
NEXT STEPS
  • Review the kinematic equations for motion under constant acceleration
  • Learn how to derive initial and final velocity using the equations of motion
  • Practice problems involving deceleration and distance to reinforce understanding
  • Explore graphical representations of motion to visualize acceleration and velocity
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone interested in understanding motion dynamics, particularly in scenarios involving deceleration and the application of kinematic equations.

LVanderlinden
Messages
4
Reaction score
0
urgent! Need find end velocity given accel., time, distance

1.The driver of a car slams on the brakes when he sees a tree blocking the road. The car slows with a constant acceleration -5.90 m/s2 for 4.45 s, making straight skid marks 60.0 m long ending at the tree. With what speed does the car then strike the tree?


The Attempt at a Solution



so I tried to find Vo using Vo=x-at^2/2
and I plugged Vo into Vf=Vi+at and got 13.4 but it was wrong.
Please help me I am so confused.
 
Physics news on Phys.org


LVanderlinden said:
1.The driver of a car slams on the brakes when he sees a tree blocking the road. The car slows with a constant acceleration -5.90 m/s2 for 4.45 s, making straight skid marks 60.0 m long ending at the tree. With what speed does the car then strike the tree?


The Attempt at a Solution



so I tried to find Vo using Vo=x-at^2/2
and I plugged Vo into Vf=Vi+at and got 13.4 but it was wrong.
Please help me I am so confused.


The equation in red is wrong. See again the equation of motion (for position vs time).
The idea of using the two equations to eliminate vo is OK.
 

Similar threads

Can terminal velocity be determined from the information given?
  • · Replies 7 ·
Replies
7
Views
1K
Help with question on motion: Avoiding a rear-end collision
  • · Replies 6 ·
Replies
6
Views
3K
Relating acceleration to distance and time
  • · Replies 5 ·
Replies
5
Views
3K
Solving for Time to Reach Ground: Calculating Velocity of Sound over 50m
  • · Replies 2 ·
Replies
2
Views
2K
Time required to change the velocity of an asteroid?
  • · Replies 23 ·
Replies
23
Views
3K
What is the Velocity of a Car at the End of the Initial 2.09-Second Interval?
  • · Replies 14 ·
Replies
14
Views
3K
Free fall velocity and distance
  • · Replies 34 ·
2
Replies
34
Views
4K
How do I calculate work in two-dimensions and find the final velocity and time?
  • · Replies 8 ·
Replies
8
Views
2K
Stopping distances on a downward slope
  • · Replies 3 ·
Replies
3
Views
2K
Finding velocity, time, and distance
  • · Replies 4 ·
Replies
4
Views
8K