Second Law of Thermodynamics — Cumulative exam Answers

Why is it advisable to wear long sleeves when students work in a chemistry lab?

When a baseball player catches a baseball, the glove "gives" or moves backward. How does this movement affect the change in momentum of the baseball?

On an ice skating rink, a girl of mass 50 kg stands stationary, face to face with a boy of mass 80 kg. The children push off of one another, and the boy moves away with a velocity of +3 m/s.

Jan made a diagram to compare speed and velocity.

According to the scientific observation that energy is conserved in a "closed system,” no machine can do work on its surrounding environment forever. This observation has been made over and over again in all sciences, and no example has been found that disproves the fact of conservation of energy.

A 2.5 kg block is launched along the ground by a spring with a spring constant of 56 N/m. The spring is initially compressed 0.75 m.

A car manufacturer wants to change its car’s design to increase the car’s acceleration. Which changes should the engineers consider making to the design?

A car with a mass of 1,500 kg requires a centripetal force of 640 N to safely follow a circular curve in the road at 13.4 m/s.

What is the most likely reason that a hypothesis would be useful even if experiments show that it is false?

The power ratings of several motors are listed in the table.An advertising agency writes marketing material for a new motor (Brand W) that has a power rating of 7,640 W. Which statement comparing the motors can they truthfully use?

A stretched spring has 5184 J of elastic potential energy and a spring constant of 16,200 N/m. What is the displacement of the spring?

A car moving south speeds up from 10 m/s to 40 m/s in 15 seconds. What is the car’s acceleration?

A twirler’s baton is 0.76 m long and spins around its center. The end of the baton has a centripetal acceleration of 47.8 m/s2.

Briana swings a ball on the end of a rope in a circle. The rope is 1.5 m long. The ball completes a full circle every 2.2 s.

Frank wrote several statements to summarize the relationship between the first and second laws of thermodynamics.1 - Thermal energy is conserved. 2 - Some thermal energy is lost and some is used to do work. 3 - Thermal energy flows from areas of higher to lower temperatures. 4 - Thermal energy can be transferred and transformed.

A wind turbine takes in energy from wind with the goal of converting it into electrical energy. Much of the wind energy is also converted into the kinetic energy of the spinning turbine and heat lost to the air around it.

What is one purpose for the peer-review process in scientific research?

Which best describes the heat that you can feel on the engine of a running car?

In which scenario is the greatest amount of work done on a wagon?

Rebekah finds that a solution of sugar in water has a volume of 1.32 fl. oz. How should she report this amount using the metric system? (1 fl. oz. = 29.6 mL)