\( \left.\qquad R .3,6 \mathrm{~m} / \mathrm{s}^{2} ; 270 \mathrm{~m} / \mathrm{s}^{2} ; 1,6 \mathrm{~m} / \mathrm{s}^{2}\right] \) Determina l'accelerazione di gravita g' esercitata dalla Terra sulla Luna, sapendo che la distanza della Luna dalla Terra è 60,25 raggi terrestri e che l'accelerazione di gravità g è \( 9,8 \mathrm{~m} / \mathrm{s}^{2} \). [R. \( \left.0,27 \mathrm{~cm} / \mathrm{s}^{2}\right] \)

4. Conjecture: Does thiction cause more energy to be wasted if the object is heavier? Why? Use the Gizmo to test this. Describe your results in your notebook or on a separate sheet.

14. Di qué tipo de movimiento tendrá un cuerpo sometido a una fuerza resultante nula y a un momento de las fuerzas no nulo. ¿Y un cuerpo sometido a una fuerza resultante no nula?

A train moving in the east direction accelerates from rest to \( 36 \mathrm{~km} / \mathrm{h} \) in 20 s . What is the average acceleration during that time interval?

3. Analyze: Friction causes work to be "wasted" as heat (which is why your hands get warm). A. Does friction waste more work on longer or shorter planes? B. How can you tell? C. Why do you think this is? [Hint: Remember the stick presses up on the item. Do your hands get warmer faster if you press them together harder as you rub?] Conjecture: Does friction cause more energy to be wasted if the object is heavier? Why? Use the Gizmo to test this. Describe your results in your notebook or on a separate sheet.

(a) (i) State the principle of superposition of waves. (ii) Distinguish between standing and stationary waves. (b) Define the following terms as applied to sound waves (i) Interference and beating. (ii) resonance and fundamental frequence.