To find the potential energy (PE) of an object due to its height above the ground, we can use the formula:
\[ PE = mgh \]
where:
- \(PE\) = potential energy (in joules)
- \(m\) = mass (in kilograms)
- \(g\) = acceleration due to gravity (approximately \(9.81 , \text{m/s}^2\))
- \(h\) = height above the ground (in meters)
Since the weight (W) of the baby is given as 20 N, we can relate weight to mass using the equation:
\[ W = mg \]
From this, we can find the mass:
\[ m = \frac{W}{g} \]
Substituting the values:
\[ m = \frac{20 , \text{N}}{9.81 , \text{m/s}^2} \approx 2.04 , \text{kg} \]
Now, we can calculate the potential energy using the height \(h = 1.5 , \text{m}\):
\[ PE = mgh = (2.04 , \text{kg})(9.81 , \text{m/s}^2)(1.5 , \text{m}) \]
Calculating this:
\[ PE \approx (2.04)(9.81)(1.5) \approx 30.04 , \text{J} \]
So, the potential energy of the baby sitting in the high chair is approximately 30.04 joules.
1 answer