Phat is the first term in this geometric sequence? What In other words, what is \( u_{1} \) ?

What is the player's average velocity between 0 and 20 seconds?

3 An unknown substance at solid phase has a freezing point of \( -22{ }^{\circ} \mathrm{C} \) and its liquid phase has a specific heat of \( 160 \mathrm{~J} / \mathrm{kg} \cdot{ }^{\circ} \mathrm{C}, 100 \mathrm{~g} \) of the above mentioned substance in the solid phase at \( -22^{\circ} \mathrm{C} \) is placed into a 0.125 kg alupninimm calorimeter cup that contains 0.10 kg of glyserine The temperature of the aluminium cup and the glycerine is initially at \( 27^{\circ} \mathrm{C} \). If all the unknown substance melts and the final temperature is \( 20^{\circ} \mathrm{C} \) at equilibrium, calculate the latent heat of fusion of the unknowl substance, provided no heat is gained from the environment or lost fro the cup. N.B : Specific heat of aluminium is \( 900 \mathrm{~J} / \mathrm{kg} .{ }^{\circ} \mathrm{C} \) Specific heat of glycerine is \( 2410 \mathrm{~J} / \mathrm{kg}{ }^{\circ} \mathrm{C} \)

What is the player's average velocity between 70 and 100 seconds?

Frecuentemente se escucha que debemos mante- ner el cuerpo hidratado y que, para ello, es necesario beber ocho vasos de agua al dia. Si se considera que un vaso de agua tiene una capacidad de aproxima- damente 200 mL, calcula cuántos litros al día se nos recomienda beber.

¿Cuál es la distancia entre \( (8,-3) \) y \( (4,-7) \) ?