What is the resistance of : a) a 1.70 m long copper wire that is 0.700 mm in diameter? b) a 20.0 cm long piece of carbon with a 2.00 mm x 2.00 mm square cross section?

(I). The resistance of the copper wire is 0.0742 Ω.

(II). The resistance of the carbon piece is 1.75 Ω.

Explanation:

Given that,

Length of copper wire = 1.70 m

Diameter = 0.700 mm

Length of carbon piece = 20.0 cm

Cross section area

(I). We need to calculate the area of copper wire

Using formula of area

We need to calculate the resistance

Using formula of resistance

Put the value into the formula

(II). We need to calculate the resistance

Using formula of resistance

Put the value into the formula

Hence, (I). The resistance of the copper wire is 0.0742 Ω.

(II). The resistance of the carbon piece is 1.75 Ω.

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.