Question

1. if an elephant weighs 30,000 n, what is its mass? weight: mass: g = 10
2. a student weighs a textbook and finds its weight is 25 n. what is the mass of the textbook? weight: mass: g = 10
3. a box has a weight of 150 n. what is its mass? weight: mass: g = 10
4. an astronaut has a mass of 70 kg. a. what is the astronauts weight on earth? b. the gravity on the moon is about 1.6m/s2. what would the astronauts weight be on the moon? (use the actual gravity value, not 10). weight: mass: g = 10
5. a bag of groceries has a mass of 12 kg. what is its weight? weight: mass: g = 10
6. a dog weighs 120 n. what is its mass? weight: mass: g = 10
7. if an object has 120n of force on earth how much mass does it have? weight: mass: g = 10

Explanation:

Step1: Recall weight - mass formula

The formula for weight $W$ is $W = mg$, where $m$ is mass and $g$ is the acceleration due to gravity. We can re - arrange it to find mass $m=\frac{W}{g}$.

Step2: Solve for mass in each case

For problem 3:

Given $W = 30000\ N$ and $g = 10\ m/s^{2}$, then $m=\frac{30000}{10}=3000\ kg$.

For problem 4:

Given $W = 25\ N$ and $g = 10\ m/s^{2}$, then $m=\frac{25}{10}=2.5\ kg$.

For problem 5:

Given $W = 150\ N$ and $g = 10\ m/s^{2}$, then $m=\frac{150}{10}=15\ kg$.

For problem 6a:

On Earth, with $m = 70\ kg$ and $g_{Earth}=9.8\ m/s^{2}$ (approx. 10 for simplicity here), the weight on Earth $W_{Earth}=mg_{Earth}=70\times10 = 700\ N$. On the moon, with $g_{moon}=1.6\ m/s^{2}$, the weight on the moon $W_{moon}=mg_{moon}=70\times1.6 = 112\ N$.

For problem 7:

Given $m = 12\ kg$ and $g = 10\ m/s^{2}$, then $W=mg=12\times10 = 120\ N$.

For problem 8:

Given $W = 120\ N$ and $g = 10\ m/s^{2}$, then $m=\frac{120}{10}=12\ kg$.

For problem 9:

Given $W = 120\ N$ and $g = 10\ m/s^{2}$, then $m=\frac{120}{10}=12\ kg$.

Answer:

1. Mass: 3000 kg
2. Mass: 2.5 kg
3. Mass: 15 kg

6a. Weight on Earth: 700 N, Weight on Moon: 112 N

1. Weight: 120 N
2. Mass: 12 kg
3. Mass: 12 kg