Why does a black ball appear black in white light?

Gravity always tries to collapse the mass of a star toward its center. What mechanism can oppose this gravitational collapse for a star? During what stages of a star's life would there be a "balance" between them?

A light plane is headed due south with a speed of 200 km/h relative to still air. After 1.00 hour, the pilot notices that they have covered only 137 km and their direction is not south but 15.0∘ east of south. What is the wind velocity?

Texas has an impending storm, and California is experiencing a water crisis. Match the technologies with the state that can use them to reduce the effects of these natural hazards.

While taking a bath, a person touches the metal case of a radio. The path through the person to the drainpipe and ground has a resistance of 4350 Ω.

If you need a technological solution to lack of water availability in a developing country, which of the following should you do before you test the design for your solution?

1. Why does the water vapour in clouds condense? 2. Explain why you can see clouds but not see the water vapour in the air

What are some similarities between electricity and gravity?

What's the difference between solids and liquids?

According to the Theory of Continental Drift, what did the Earth's continents look like 255 million years ago?

What is the emf of a battery that increases the electric potential energy of 0.060 CC of charge by 0.70 JJ as it moves it from the negative to the positive terminal?