What is the frequency of a wave that has a wavelength of 20 cm and a speed of 10 m/s?

50 Hz

200 Hz

0.5 Hz

10 Hz

In the early 1960s the strange optical emission lines from starlike objects that also were producing trementdous radio signals confused scientists.

Explain how atoms are aligned in a magnet in terms of the North and South poles.

A capacitor consists of a set of two parallel plates of area A separated by a distance d. This capacitor is connected to a battery that maintains a constant potential difference V across the plates.

Meg lifted a box of books with a mass of 20 kg from the floor to a shelf 1.4 m off the ground. The applied force was equal to the weight of the box of books. How much work did Meg do?

The speed of light is 3.00*108m/s. How long does it take for light to travel from Earth to the Moon and back again? Express your answer using two significant figures.

A substance has a density of 13.5 g/cm3. What is the volume of a 50 g block of this substance?

Select all of the answers that apply. Which statements are true regarding the scientific evidence supporting the big bang theory? Researchers found cosmic microwave background radiation, which is a heat imprint left over from the big bang.

How are magnetic poles and electrical charges similar? A. Their same forces repel each other, and their opposite forces attract each other. B. Their same forces attract each other, and their opposite forces repel each other. C.

As part of his meal, a workman has a cup containing a hot drink. In order to keep the drink hot whilst he eats the rest of his meal, he covers the cup, as shown in the figure. Which sources of energy loss does this action reduce? Tick two boxes.

When energy is transformed, the amount of usable energy?