Question

complete the following table. be sure each of your answer entries has the correct number of significant digits.

food
energy content when eaten
cal
kcal
kj
a cup of cooked green peas
1.25×10⁵

a raw carrot

30.0

a chocolate chip cookie

188.

Explanation:

Step1: Convert cal to kcal for green peas

Since \(1\ kcal = 1000\ cal\), for \(1.25\times10^{5}\ cal\), we divide by \(1000\).
\(\frac{1.25\times 10^{5}}{1000}=125\ kcal\)

Step2: Convert cal to kJ for green peas

Since \(1\ cal = 4.184\ J\), then \(1.25\times10^{5}\ cal\times4.184\ J/cal = 523000\ J=523\ kJ\)

Step3: Convert kcal to cal for raw carrot

Since \(1\ kcal = 1000\ cal\), for \(30.0\ kcal\), we multiply by \(1000\). \(30.0\times1000 = 3.00\times10^{4}\ cal\)

Step4: Convert kcal to kJ for raw carrot

Since \(1\ kcal = 4.184\ kJ\), for \(30.0\ kcal\), \(30.0\times4.184=125.52\ kJ\approx126\ kJ\)

Step5: Convert kJ to cal for chocolate chip cookie

Since \(1\ J = 0.239\ cal\), for \(188\ kJ = 188000\ J\). \(188000\ J\times0.239\ cal/J=45032\ cal\approx4.50\times 10^{4}\ cal\)

Step6: Convert kJ to kcal for chocolate chip cookie

Since \(1\ kcal = 4.184\ kJ\), \(\frac{188}{4.184}\approx45.0\ kcal\)

Answer:

food	energy content when eaten
a raw carrot	\(3.00\times 10^{4}\ cal\), \(126\ kJ\)
a chocolate chip cookie	\(4.50\times 10^{4}\ cal\), \(45.0\ kcal\)