An element's atomic number is 39. How many protons would an atom of this element have?

How strong is the electric field between the plates of a 0.86 µf air-gap capacitor if they are 2.0 mm apart and each has a charge of 64 µc?

if you use the compound pulley, you will need to pull twice the distance but with less force. the force you need is equal to one half the weight of the box plus 25 N. what is the force needed?

A student takes 5 min to blow dry hair with a 2300 W blow dryer. How much energy dissipated by the blow dryer during this time?

A rock is dropped from a height of 2.5 meters. What is its velocity when it reaches the ground?

A powerboat accelerates along a straight path from 0 km/hr to 99.8 km/hr in 10.0 s. Find the average acceleration of the boat in meters per second squared.

Why is copper a pure substance

Over the course of a martian year, what are the ranges of the rms speeds of the co2 molecules.

Why is it important that all scientists use the metric system?.

Whay is moon non-lominous body

How many (whole number of) 91 kg people can safely occupy an elevator that can hold a maximum mass of exactly 1 metric ton? A metric ton is 1.000 * 103 kg. Answer in units of people.