9. A toy cart at the end of a string 0.70 m long moves in a circle on a table. The cart has a mass of 2 kg and the string has a breaking strength of 40 N. Calculate the maximum speed the cart can attain without breaking the string? \( (3.74 \mathrm{~m} / \mathrm{s}) \)

Un cilindro graduato contiene inizialmente un volume d'acqua pari a \( (200 \pm 5) \mathrm{cm}^{3} \). Un oggetto viene immers completamente in acqua e il volume dell'acqua sale \( (345 \pm 5) \mathrm{cm}^{3} \). Calcola il volume dell'oggetto.

Find the current through section \( P Q \) of length \( a=62.0 \mathrm{~cm} \) shown in Figure P31.11. The circuit is located in a magnetic field whose magnitude varies with time according to the expression \( B=\left(1.00 \times 10^{-3} \mathrm{~T} / \mathrm{s}\right) t \). Assume the resistance per length of the wire is \( 0.098 \Omega / \mathrm{m} \). Magnitude

4. Un auto adquiere una velocidad de \( 50 \mathrm{~km} / \mathrm{h} \) al poniente en 3.5 s . ¿Cuál es aceleración en \( \mathrm{m} / \mathrm{s}^{2} \) ?

2. STEM Density is measured in units of mass per unit of volume. It can be thought of as a unit rate. The mass of a block of aluminum is 9.45 grams. The volume is 3.5 cubic centimeters \( \left(\mathrm{cm}^{3}\right) \). What is the density of the aluminum?

4. A voltage of 80 volts is applied to a resistor and the current going through is found to be 200 mA . a) Convert the current to Amperes. Answer : b) Calculate the resistance of the resistor,