Calculating Work Needed to Stop a 1100 kg Car | KE=1/2mv² | 118km/h Speed

  • Thread starter Thread starter lim
  • Start date Start date
  • Tags Tags
    Car Work
Click For Summary
SUMMARY

The discussion focuses on calculating the work required to stop a 1100 kg car traveling at 118 km/h using the kinetic energy formula KE = 1/2 mv². The correct conversion of speed from kilometers per hour to meters per second is crucial, resulting in a speed of 32.78 m/s. The kinetic energy is calculated as KE = 1/2 * 1100 kg * (32.78 m/s)², yielding a value of approximately 5.91 x 10^7 joules. This value represents the work needed to bring the car to a complete stop.

PREREQUISITES
  • Understanding of kinetic energy and the formula KE = 1/2 mv²
  • Ability to convert units from kilometers per hour to meters per second
  • Basic algebra skills for manipulating equations
  • Familiarity with the concept of work in physics
NEXT STEPS
  • Learn about the principles of energy conservation in physics
  • Study the effects of mass and velocity on kinetic energy
  • Explore real-world applications of work-energy principles in automotive safety
  • Investigate unit conversion techniques for speed and energy calculations
USEFUL FOR

Students studying physics, automotive engineers, and anyone interested in the calculations related to vehicle dynamics and stopping distances.

lim
Messages
19
Reaction score
0

Homework Statement



How much work must be done to stop a 1100 kg car traveling at 118 km/hr?

Homework Equations


Ei + W= Ef
KE= 1/2mv^2

The Attempt at a Solution



KE= 1/2mv^2

118kmx1000m/360s= 327.78

327.78^2= 107437.76

107437.76x1100= 118181537.9

118181537.9/2 = -5.91x10^7

thanks for any help
 
Physics news on Phys.org
lim said:
118kmx1000m/360s= 327.78
Recheck that conversion: How many seconds in an hour?
 
do KE = 1/2 (1100 kg)(118*(1000/3600))^2
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 26 ·
Replies
26
Views
4K
Replies
8
Views
3K
  • · Replies 11 ·
Replies
11
Views
3K
Replies
20
Views
4K
  • · Replies 19 ·
Replies
19
Views
3K