If sunlight peaks at 0.55 m wavelength, this infers a surface temperature of the sun of how many thousand degrees Kelvin?
A) 9.5
B) 5.3
C) 2.5
D) 25.
E) 15.
Question 2Bert and Ernie are two friends of the same age. Bert visits a nearby star system on a spaceship that travels close to the speed of light while Ernie stays at home. Which of the following will be true on Bert's return to Earth?
A) Ernie will be younger than Bert
B) Ernie will be older than Bert
C) Bert and Ernie will still be the same age
D) Ernie will not have been born
Question 3A ball with diameter 10. cm rolls without slipping on a horizontal table top. The moment of inertia of the ball is 2.2 10-3 kg-m2 and its translational speed is 0.45 m/s.
(a) What is its angular speed about its center of mass?
(b) What is its rotational kinetic energy?
(c) What is its angular momentum?
Question 4A 4.0 cm tall object is placed 50 cm away from a converging lens of focal length 25 cm. What is the nature and location of the image?
A) The image is real, 2.5 cm tall, 25 cm on the same side as object.
B) The image is virtual, 2.5 cm tall, 25 cm on the other side of the lens.
C) The image is virtual, 2.0 cm tall, 15 cm on the other side of the lens.
D) The image is virtual, 4.0 cm tall, 50 cm on the same side as object.
E) The image is real, 4.0 cm tall, 50 cm on the other side of the lens.
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