If 50% of a radioactive element remains after 4000years what is the half life

A plasma wave moving through a plasma has a frequency of 109 Hz and a speed of 3.0 * 107 m/s. What is the wavelength of this wave?

What is the mass of an object if a force of 34 N produces an acceleration of 4 m/s/s?

Based upon what you have learned in the previous lesson, Risk Factors and Behaviors, write an essay of no less than 200 words on health behaviors, risk factors, and prevention of coronary artery disease (CAD) through exercise.

A football player kicks a ball with a mass of 0.42 kg. The average acceleration of the football was 14.8 m/s². How much force did the kicker supply to the football? A. 6.22 m/s² B. 35.24 m/s² C. 35.24 N D. 6.22 N

A sound wave has a frequency of 295 Hz and travels the length of a football field, 91.4 m in 0.506 s. What is the period of the wave?

What is the direction of the force when an object moved in a circle

An observer notes that the pitch of a sound is becoming progressively higher. the observer can conclude that the sound is moving

A falling back in mid air has what

What objects are often arranged by their properties

Which nuclei is not radioactive? A. Am-241 B. Mg-24 C. Pu-241 D. U-238