Yusuf loads bricks onto a pallet. Each brick has a mass of 3.0 kg.
What is one brick's weight, in newtons? Take g = 9.8 N/kg.
You know the equation: w = mg.
Finding a weight is a routine. The same three steps work every time.
Step 1: write down the values in the question, and mark the unknown.
Step 2: write down the equation.
Step 3: substitute in the values, and calculate.
The result line always carries its unit: newtons.
The g you substitute is the local value: 9.8 N/kg on Earth, 1.6 N/kg on the Moon.
The routine itself does not change from place to place.
A brick has a mass of 3.0 kg. Take g = 9.8 N/kg. Calculate the brick's weight.
Write down the values:
m = 3.0 kg, g = 9.8 N/kg, w = ?
Write down the equation:
w = mg
Substitute in the values, and calculate:
w = 3.0 × 9.8 = 29.4
The brick weighs 29.4 N, about 29 N.
The same 3.0 kg brick rides to the Moon, where g = 1.6 N/kg. Calculate its weight there.
Write down the values:
m = 3.0 kg, g = 1.6 N/kg, w = ?
Write down the equation:
w = mg
Substitute in the values, and calculate:
w = 3.0 × 1.6 = 4.8
On the Moon the brick weighs 4.8 N.
A bowling ball has a mass of 6.0 kg. Take g = 9.8 N/kg. Enter its weight in N.
A gymnast has a mass of 45 kg. Take g = 9.8 N/kg. Enter her weight in N.
A textbook has a mass of 0.80 kg. Take g = 9.8 N/kg. Enter its weight in N.
On the Moon, g = 1.6 N/kg. An oxygen tank there has a mass of 7.5 kg. Enter its weight on the Moon in N.
A vending machine has a mass of 120 kg. Take g = 9.8 N/kg. Enter its weight in N.
On Mars, g = 3.7 N/kg. A rover wheel there has a mass of 20 kg. Enter its weight on Mars in N.
A packed suitcase has a mass of 14 kg. Take g = 9.8 N/kg. Enter its weight in N.
Demi wheels her camping cooler to the campsite. The cooler has a mass of 9.5 kg. Take g = 9.8 N/kg. Enter its weight in N.
On Mars, g = 3.7 N/kg. An astronaut together with her suit has a mass of 65 kg. Enter their weight on Mars in N.