The gravitational force between the sun and mercury

 Mercury Fact Sheet Mercury's orbital velocity is 1.59 times that of Earth while its angular velocity is 1/. 241 = 4.15 times that of Earth. Their product, 6.6, is therefore Sun's pull on Mercury as a multiple of the Sun's pull on Earth, whatever that might be

answer: a ball

explanation: because it will bounce

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.