Sharpening a pencil leaves behind pencil shavings. is sharpening a pencil a physical change or a chemical change

The sun's radiation has different wavelengths. the shorter is the radiation's wavelength, the weaker is the radiation's energy. true false

A 2290 kg car traveling to the west at 22.3 m/s slows down uniformly. How long would it take the car to come to a stop if the force on the car is 8930 N to the east? Let East be positive. Answer in units of s.

What is the requirement for a core to be used in an electromagnet?

Algorithm to determine number of shortest paths between two nodes

Which sequence lists types of material in order from least conductive to most conductive

Calculate the temperature of and power-per-area radiated from a blackbody if the spectral intensity density peaks at (a) gamma rays, λ = 1.50*10-14 m; (b) x rays, 1.50 nm; (c) red light, 640 nm; (d) broadcast television waves, 1.

How has increased energy use associated with scientific advancements affected society? a. It has led to an increase of the concentration of atmospheric carbon dioxide. b. It has led to an increase in hazardous wastes from mining operations. c.

Water is moving with a speed of 5.7 m/s through a pipe with a cross-sectional area of 4.8 cm2. The water gradually descends 9.2 m as the pipe increases to 8.8 cm2. (a) What is the speed at the lower level? (b) If the pressure at the upper level is 1.

Is Kepler's constant the same for moons orbiting a planet as it is for planets orbiting the sun? Why?

In which one of the following situations is zero net work done? A) A ball rolls down an inclined plane. B) A physics student stretches a spring. C) A projectile falls toward the surface of Earth.