Explain why machine can"t be

100% efficient practically?

The air speed of a plane is defined as its velocity with respect to the surrounding air, or in other words how fast the plane would move in still air. The ground speed is the speed of the plane as measured from the ground.

what types of teeth are characteristic of animals that eat plants and animals that eat other animals?

The size of a force vector shows; A. the direction of the force B. the magnitude of the force C. the length the object will move because of the force D. the acceleration of the object

A bullet can travel at a speed of over 1000 m/s. When a bullet is fired from a rifle, the actual firing makes a distinctive sound, but people at a distance may hear a second, different sound that is even louder. Explain the source of this sound.

A child playing in a swimming pool realizes that it is easy to push a small, inflated ball under the surface of the water, whereas a large ball requires a lot of force.

If the resistance of a circuit increases, that means that the current has to

One watt is equal to which of these values? 1 joule/hour 1 joule-hour 1 joule/second 1 joule-second

What are some of the benefits of learned optimism that have been found in research? O A. Fewer health problems O O B. All of these C. Making more money O D. A lower divorce rate

Katie runs 6 km in 0.6 hour, then 5 km in 0.5 hour. Katie's average speed is __ per hour.

A derived unit is a combination of fundamental units. Which of the following is an example of a derived unit? a) centimeter (used to measure distance) b) gram (used to measure mass) c) cubic centimeter (used to measure volume)