What causes the increase in pitch as an ambulance siren moves toward you? the sound waves become compressed. the amplitude of the sound waves changes. the sound waves spread farther apart. the speed of the sound waves changes?

Estimate the radiation pressure due to a bulb that emits 25 W of EM radiation at a distance of 9.5 cm from the center of the bulb. Assume that light is completely absorbed.

What are the common tools scientists use to measure length, mass, and, liquid volumes

Which class of elements is most effective at conducting electricity and heat

Determine the heat given off to the surroundings when 9.0 g of aluminum reacts according to the equation 2al + fe2o3 → al2o3 + 2fe, δh°rxn = - 849 kj/mol.

The blocking of sunlight to earth that occurs when the moon is directly between the sun and earth

What units are used for gravitational potential energy? Write the name, not the symbol.

A 7.5 kg block is placed on a table. If it's bottom surface area is 0.6m2, how much pressure does the block exert on the tabletop? A. 376.5 Pa B. 73.5 Pa C. 226.5 Pa D. 122.5 Pa

A boulder of mass 2000 kg is at the top of a cliff of height 220 m. Determine how fast the boulder will be moving when it strikes the dirt below.

Which of the following statements are true? Check all that apply. O A positive charge and a negative charge attract each other. O Electric charge is conserved. O Two positive charges attract each other. O A neutral object contains no charge.

You push a shopping cart filled with groceries (total mass = 20 kg) by applying a force to the cart 30° from the horizontal. if the force you apply has a magnitude of 86 n, what is the cart's acceleration? assume negligible friction.