Question

A medium-sized peach provides about 59.0 Calories of energy.

A) Convert 59.0 Cal to joules.

B) Suppose that amount of energy is transformed into kinetic energy of a 1.83 kg object initially at rest. Calculate the final speed of the object (in m/s).

C)

If that same amount of energy is added to 3.79 kg (about 1 gal) of water at 19.7°C, what is the water's final temperature (in °C)? The specific heat of water is

c = 4186 j/(kg*c)

Answer 1

Amount of energy provided by a medium-sized peach = E = 59 Calories

1 Calorie = 4184 J

Converting the energy of the peach from Calories to Joules,

E = 59 x (4184) J

E = 246856 J

Mass of the object = m = 1.83 kg

Initial speed of the object = v₁ = 0 m/s (At rest)

Final speed of the object = v₂

The energy of the peach is transformed into the kinetic energy of the object therefore,

v₂ = 519.4 m/s

Mass of the water = M = 3.79 kg

Initial temperature of the water = T₁ = 19.7 ^oC

Final temperature of the water = T₂

Specific heat of water = C = 4186 J/(kg.^oC)

The energy of the peach is converted into heat energy to heat up the water therefore,

E = MC(T₂ - T₁)

246856 = (3.79)(4186)(T₂ - 19.7)

15.56 = T₂ - 19.7

T₂ = 35.26 ^oC

A) Conversion of 59 Calories to Joules = 246856 J

B) Final speed of the object = 519.4 m/s

C) Final temperature of the water = 35.26 ^oC