Let's solve the exercises provided step-by-step.

Exercises 1-6

The formula given is $W = f \cdot d$, where:

• $f$ is the force,
• $d$ is the distance,
• $W$ is the work done.

Let's compute $W$ for each exercise.

1. $f = 30$, $d = 20$ $W = 30 \times 20 = 600$

2. $f = 17$, $d = 9$ $W = 17 \times 9 = 153$

3. $f = 1125$, $d = 10$ $W = 1125 \times 10 = 11250$

4. $f = 203$, $d = 27$ $W = 203 \times 27 = 5481$

5. $f = 176$, $d = 326$ $W = 176 \times 326 = 57376$

6. $f = 2400$, $d = 120$ $W = 2400 \times 120 = 288000$

Exercises 7-9

These questions use formulas from page 19, where likely each formula corresponds to physical relationships involving mass, acceleration, voltage, resistance, etc. Let's assume the following standard formulas commonly used in physics:

1. Force (F = m * a) for Exercise 7.
2. Power (P = V * I), where $V = I \cdot R$, so rearranged for $P = V^2 / R$ for Exercise 8.
3. Current (I = V / R) for Exercise 9.

Solving Each:

7. If $m = 1600$ and $a = 24$, find $f$. $f = m \times a = 1600 \times 24 = 38400$

8. If $V = 120$ and $R = 24$, find $P$. $P = \frac{V^2}{R} = \frac{120^2}{24} = \frac{14400}{24} = 600$

9. If $E = 120$ and $R = 15$, find $I$. $I = \frac{E}{R} = \frac{120}{15} = 8$

Would you like further details on any specific exercise?

Additional Questions for Practice

1. If $f = 50$ and $d = 30$, what is the work $W$ done?
2. Given $m = 2000$ and $a = 15$, find the force $f$.
3. If $V = 240$ and $R = 30$, calculate the power $P$.
4. Suppose $E = 150$ and $R = 10$; find the current $I$.
5. If the force doubles but the distance remains constant, how does that affect $W$?

Tip

When calculating work, remember that it's always the product of force and distance. Units are essential: force in Newtons (N) and distance in meters (m) yield work in Joules (J).