Los automóviles actuales tienen “parachoques de 5 mi/h (8 km/h)” diseñados para comprimirse y rebotar elásticamente sin ningún daño físico a rapideces menores a 8 km/h. Si el material de los parachoques se deforma permanentemente después de una compresión de 1.5 cm, pero permanecen como un resorte elástico hasta ese punto, ¿cuál debe ser la constante efectiva de resorte del material del parachoques, suponiendo que el automóvil tiene una masa de 1050 kg y que se prueba chocándolo contra una pared sólida?

k = 23045 N/m

Explanation:

To find the spring constant, you take into account the maximum elastic potential energy that the spring can support. The kinetic energy of the car must be, at least, equal to elastic potential energy of the spring when it is compressed to its limit. Then, you have:

   (1)

M: mass of the car = 1050 kg

k: spring constant = ?

v: velocity of the car = 8 km/h

x: maximum compression of the spring = 1.5 cm = 0.015m

You solve the equation (1) for k. But first you convert the velocity v to m/s:

The spring constant is 23045 N/m

question: ray weighs 100 kilograms, his wrestling partner, bobby, weighs 50 kilograms. if ray moves at 4 m s , how fast will bobby have to run at him to apply an equal amount of kinetic energy?

answer: 8 m/s he needs to run twice as fast to keep up so he has some work to do

explanation:   if the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.

question answered by

(jacemorris04)