Which of the following is a cause for limitations of scientific models?

a. they are never based on experimentation.

b. they are used for prediction.

c. it is not possible to change scientific models.

d. they are based on current knowledge.?

Now imagine a person dragging a 50 kg box along the ground with a rope, as in the drawing below. The person exerts 50 N of force while moving the box 201 10 s. Suppose also that friction is acting with 30 N of force between the box and the ground

a value of pH 7.0 indicates A) a zero hydrogen-ion concentration B) the lowest hydrogen-ion concentration C) the highest hydrogen-ion concentration D) equal hydrogen and hydroxide-ion concentration

In a wave, what do you call the difference from crest to crest or trough to trough amplitude crest frequency wavelength

Most alcohilic attribute deaths are caused by?

A sky diver steps from a high-flying helicopter. If there were no air resis - tance, how fast would she be falling at the end of a 12-second jump?

A 111.6 g sample of iron was heated from 0°C to 20°C. It absorbed 1004 J of energy. What is the specific heat capacity of iron?

A car is driving towards a brick wall at a constant velocity (don't try this at home!) and the driver honks the horn of the car. the sound of the horn reflects from the wall and the echo is heard by the driver.

Mass number of an atom with 11 protons

Which of the following elements is the most reactive? Beryllium Calcium Magnesium Barium

A flash of white light containing all the colors of the visible spectrum in air shines straight down on the surface of a pool.