Help me plzzz. i’ll give brainliest!!! 1. In the 1950's, an experimental train that had a mass of 2.50 x 10* kg, was powered across
a level track by a jet engine that produces a thrust of 5.00 x 10' N for a distance of 5.00 x
107 m. What is the final speed of the train if there was no friction?

2. A hockey puck is accelerated, using a hockey stick, over a smooth, level ice surface. The
puck has a mass of 0.400 kg and is moved by the stick for a distance of 0.800 m. What
was the average force applied to the puck if the final speed is 25.0 m/s?

Air is held within a frictionless piston-cylinder container, which is oriented vertically. the mass of the piston is 0.45 kg and the cross-sectional area is 0.0030 m2. initially (state 1) the pressure of the gas is sufficient to support the weight of the piston as well as the force exerted by the atmospheric pressure ( 101.32 kpa). the volume occupied by the air within the cylinder in state 1 is 1.00 liter. one end of a spring (with spring constant k = 1000 n/m) is attached to the top of the piston, while the other end of the spring is attached to a stage that can move vertically. initially the spring is undeflected and therefore exerts no force. then the stage is then moved quasistatically downward a distance of 10.0 cm, at which point the system reaches state 2. the piston-cylinder is not insulated; rather it remains in diathermal contact with the surroundings, which are at a constant temperature of 300 k. what is the change of pressure within the container?

In a system, when potential energy decreases, then entropy also decreases. true false

Examine the nuclear reacti why is this classified as a nuclear reaction rather than a chemical reaction? it is not balanced. a new compound is formed. a change has occurred in a nucleus. a new element has been formed.