Question 2

To determine the mass of the second rocket, we first need to calculate the acceleration of the first rocket using Newton's second law, which states:

\[
F = ma
\]

where \( F \) is the force, \( m \) is the mass, and \( a \) is the acceleration.

For the first rocket:
- Force \( F = 100 \, \text{N} \)
- Mass \( m = 0.8 \, \text{kg} \)

We can rearrange the equation to solve for acceleration \( a \):

\[
a = \frac{F}{m} = \frac{100 \, \text{N}}{0.8 \, \text{kg}} = 125 \, \text{m/s}^2
\]

The second rocket is designed to accelerate at half the rate of the first rocket, so:

\[
a_{2} = \frac{a_{1}}{2} = \frac{125 \, \text{m/s}^2}{2} = 62.5 \, \text{m/s}^2
\]

Now, we can use the same force of 100 N to find the mass of the second rocket using the formula again:

\[
m_2 = \frac{F}{a_2} = \frac{100 \, \text{N}}{62.5 \, \text{m/s}^2} = 1.6 \, \text{kg}
\]

Thus, the mass of the second rocket is:

**Answer: b) 1.6 kg**