Work in the amount of 280 J is done in lifting an object a distance of 4.0 m in a time of 7.0 s
a. How much force did it take to lift the object?
b. What was the power input?
a. 70 N
b. 40 W
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A ray of white light, incident upon a glass prism, is dispersed into its various color components. Which one of the following colors experiences the greatest angle of deviation?
a. orange b. violet c. red d. green
Red giants
A) are mature stars that are fusing hydrogen into helium in their cores B) are dead stars C) have exhausted their nuclear fuel and are in the process of dying D) are in the process of forming
Bert says that a charged particle in a vacuum can travel in a helix only if a uniform electric field and a uniform magnetic field are both present and both parallel to the axis of the helix. Stuart says that only a magnetic field with a component parallel to the axis of the helix is needed. Which one, if either, is correct, and why?
a. Bert, because the charged particle's velocity can have a vertical component only if an electric field in the vertical direction is present. b. Stuart, because a component of velocity in the vertical direction is not changed by a vertical component of a magnetic field. c. Bert, because a component of velocity in the vertical direction is changed by a vertical component of a magnetic field. d. Stuart, because an electric field in the vertical direction would cause the particle to come to a complete stop. e. Neither, because particles cannot move in helical paths in the presence of magnetic and electric fields.
According to Gwen back on Earth, about how long does it take Jackie to reach Vega?
A) about a month B) about 10 years C) about 25 years D) about 100 years E) about 1,000 years