Suppose a ball is thrown straight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is going up
A) Both its velocity and its acceleration point upward.
B) Its velocity points upward and its acceleration points downward.
C) Its velocity points downward and its acceleration points upward.
D) Both its velocity and its acceleration points downward.
E) Neither velocity nor acceleration can be determined without additional information.
B
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According to modern scientific dating techniques, approximately how long ago did Earth and the other planets of our solar system form?
A) 4.5 billion years B) 10,000 years C) 4.5 million years D) 14 billion years
On the earth, when an astronaut throws a 0.250-kg stone vertically upward, it returns to his hand a time T later. On planet X he finds that, under the same circumstances, the stone returns to his hand in 2T
In both cases, he throws the stone with the same initial velocity and it feels negligible air resistance. The acceleration due to gravity on planet X (in terms of g) is A) g/4. B) g/2. C) g/ . D) g . E) 2g.
Based on our current Gregorian calendar, which of the following years is not a leap year?
A) 2000 B) 2004 C) 2008 D) 2012 E) All of the above are leap years.
An ideal heat engine is operating between high and low temperature reservoirs. Suppose that now the low temperature reservoir has its temperature lowered, but no other changes are made. This temperature change affects the engine efficiency in which of the following ways?
A. The efficiency increases B. The efficiency is unchanged C. The efficiency decreases D. There is now no way to calculate the efficiency