A2.5-kg box, sliding on a rough horizontal surface, has a speed of 1.2 m/s when it makes contact with a spring. the block comes to a momentary halt when the compression of the spring is 2.0 cm. the thermal energy generated by friction, from the instant the block makes contact with the spring until it comes to a momentary halt, is 0.5 j (b) what is the coefficient of kinetic friction between the box and the rough surface?

Explanation:

Given

mass of box

speed

compression in the spring

Total Initial energy

Thermal energy generated is

this thermal energy is produced by friction force

Work done by Friction Force is

where

contradicts the fact that friction is present because shows there is no friction so either surface is friction less or compression in the system should be more than 2 cm

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.