Radon has a half-life of 56s. After what time will it's activity be reduced to (a) 90% (b) 50% (c) 10% of it's initial value​

Which statement best describes copper? a. it has a low resistance and prevents charges from moving freely. b it has a high resistance and allows charges to move freely. c. it has a high resistance and prevents charges from moving freely. d. it has a low resistance and allows charges to move freely

Madison pushes with a 210-n horizontal force on a 24-kg crate of coffee resting on a warehouse floor. the force of friction on the crate is 74 n. what is the acceleration?

The mass of the sun is 1.99×1030kg and its distance to the earth is 1.50×1011m. what is the gravitational force of the sun on the earth?