Final answer:
The potential energy of a baby weighing 20N sitting in a high chair at a height of 1.5m is 30 joules, calculated using the formula for gravitational potential energy PE = mgh, with the given weight and height.
Step-by-step explanation:
To find the energy of a baby who weighs 20N sitting in a high chair 1.5m high, we need to calculate the gravitational potential energy (PE). This form of energy is given by the formula PE = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m/s2), and h is the height above the reference point in meters. Since we have the weight force (W = mg), we can rearrange the formula to find PE = Wh. In this case, we use W = 20N and h = 1.5m to get the potential energy:
PE = 20N * 1.5m = 30J
Therefore, the potential energy of the baby sitting in the high chair is 30 joules (J).