كرة كتلتها و 200 مربوطة بنهاية خيط طوله m 1 تتحرك حركة دائرية منتظمة في مسار دائري افقي ، اذا كانت الكرة تدور دورتين في الثانية ، فإن مقدار قوة الشد في الخيط بوحدة النيوتن تقريبا
تساوي :

Awater balloon launcher uses an elastic band with a spring constant of 115 n/m to use thee launcher you stretch thee band back with a balloon n it the water balloons have a mass of 1.3 kg a) if you stretch the band by 0.8 m, what elastic force will the band exert? b) with the band stretched 0.8 m, how much elastic potential energy is stored in the spring? c) if you release the band, it pushes forward. what is the kinetic energy of the balloon when it reaches the natural length of the band? d) what is the speed of the balloon when it reaches the natural length of the band?

Which of the following list the divisions of the geologic time scale in order from longest to shortest

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is as it changes into other forms of energy.