A heavy sled and a light sled, both moving horizontally with the same speed, suddenly slide onto a rough patch of snow and eventually come to a stop. The coefficient of kinetic friction between the sleds and the rough snow is the same for both of them.

Which of the following statements about these sleds are correct?

A) Both sleds will slide the same distance on the rough snow before stopping.

B) The heavy sled will slide farther on the rough snow than the light sled.

C) The light sled will slide farther on the rough snow than the heavy sled.

D) The friction from the snow will do the same amount of work on both sleds.

A) Both sleds will slide the same distance on the rough snow before stopping.

D) The friction from the snow will do more negative work on the heavy sled than on the light sled.

Explanation:The coefficient of kinetic friction is the ratio of the force of friction of a given object or material to the normal force acting on it,it depends mainly on the nature of the surface in consideration. The higher the roughness of a surface is, the higher the coefficient of kinetic friction. For an object at rest on a plane surface with no other force acting on it,the normal force will be considered as the force of gravity.

The correct answers is option A) "Both sleds will slide the same distance on the rough snow before stopping".

Explanation:

For objects moving horizontally at the same speed, an equal coefficient of kinetic friction would mean that both objects will move the same distance before stopping, independently of their mass. The coefficient of kinetic friction is obtain from dividing the force needed to pull an object between the force that holds or prevents the object from moving. The coefficient of kinetic friction is a dimensionless scalar, which means that is independent of the size of the object because it depends only in the forces that act upon it.

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia