Apositively charged insulating rod is brought close to an object that is suspended by a string. if the object is repelled away from the rod we can conclude: a) the object is positively charged b) the object is negatively charged c) the object is an insulator d) the object is a conductor e) none of the above two small charged objects repel each other with a force f when separated by a distance d. if the charge on each object is reduced to one-fourth of its original value and the distance between them is reduced to d/2 the force becomes: a) f/16 b) f/8 c) f/4 d) f/2 e) f

According to newton's second law, when the same force is applied to two objects of different masses, a the object with greater mass will experience a great acceleration, and the object with less mass will experience an even greater acceleration, b. the object with greater mass will experience a smaller acceleration, and the object with less mass will experience a greater acceleration, c. the object with greater mass will experience a greater acceleration, and the object with less mass will experience a smaller acceleration, d. the object with greater mass will experience a small acceleration, and the object with less mass will experience an even smaller acceleration.

Consider a 1000 w iron whose base plate is made of 0.5 cm thick aluminum alloy 2024-t6 (ρ = 2770 kg/m3 and cp = 875 j/kg°c). the base plate has a surface area of 0.03 m2. initially, the iron is in thermal equilibrium with the ambient air at 22°c. assuming 90% of the heat generated in the resistance wires is transferred to the plate, determine the minimum time needed for the plate temperature to reach 200°c.

What is a subatomic particle with a negative charge and very little mass?