user: In my lab today, I'm working on two separate problems. First, I'm dealing with an electrostatics challenge where I have a sphere carrying a charge of 5 coulombs and it's exposed to an electric potential of 10 volts. I need to figure out the electrostatic potential energy for this setup. Also, I have a geometric task where I'm looking at a circle with a 7-unit radius, and I need to calculate its area. Could you provide me with the electrostatic potential energy for the charged sphere and the area of the circle?

Available functions:
name: calculate_electrostatic_potential_energy
description: Calculates the electrostatic potential energy.
parameters: type: dict
properties: charge: type: float
description: The charge of the object, in coulombs.
voltage: type: float
description: The voltage of the object, in volts.
required: charge
voltage
name: geometry_area_circle
description: Calculates the area of a circle.
parameters: type: dict
properties: radius: type: integer
description: The radius of the circle, in feet.
required: radius

Ground truth function call(s):
calculate_electrostatic_potential_energy(charge=5.0, voltage=10.0)
geometry_area_circle(radius=7)