Cumulative Exam — Cumulative exam Answers

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.

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?

Which is the best example of kinetic energy?

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

Two animals that can be found at the Grand Canyon include the Abert’s and Kaibab squirrels. The Abert’s squirrel is found at the south rim of the canyon and in a few surrounding states. The Kaibab squirrel, however, can only be found at the canyon’s north rim, mainly on the Kaibab Plateau. The Kaibab squirrel is not found anywhere else in the world. Scientists believe that the squirrels are actually closely related and have developed separately as a result of geographic isolation. It is possible that the squirrels were separated by plateau erosion that separated the forests and isolated the Kaibab population. Some scientists are studying if the squirrels are now two separate species or if the Kaibab squirrel is simply a subspecies of the Abert’s squirrel. Separate species are unable to reproduce with each other. Which evidence would be used to support the claim that the squirrels are two separate species?

What is the approximate tangential speed of an object orbiting Earth with a radius of 1.8 × 108 m and a period of 2.2 × 104 s?

If all else stays the same, which change could be made to cause an increase in the gravitational force on a space shuttle?

The image shows a pendulum that is released from rest at point A.

The gravitational force between two objects is 1600 N. What will be the gravitational force between the objects if the distance between them doubles?

How do the ongoing processes of scientific investigation and technological design interact with each other?

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

A ball moves in a circle at the end of a string, as shown.

The MSDS for propane gives it a health rating of 1, a flammability rating of 4, and a reactivity rating of 0. According to the MSDS, which best describes propane?

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.

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.

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?increase the force that the engine providesdecrease the force that the engine providesincrease the mass of the cardecrease the mass of the carincrease the top velocity the car can traveldecrease the top velocity the car can travel

What is the horizontal acceleration of a ball that is launched horizontally with a velocity of 5.6 m/s?

The diagram shows two vectors that point west and north.

A car travels straight for 20 miles on a road that is 30° north of east. What is the east component of the car’s displacement to the nearest tenth of a mile?

The energy transfer diagram represents the energy of a light bulb.