An 8.00-m-long length of wire has a resistance of 4.00 Ω. The wire is uniformly stretched to a length of 16.0 m. Find the resistance of the wire after it has been stretched.

8.00Ω

The resistance (R) of a wire is related to the length (L) of the wire as follows;

R = ρL/ A           ----------------(i)

Where;

ρ = resistivity of the wire

A = crossectional area of the wire.

Taking the resistivity and area constant, equation (i) can be re-written as;

R = k L        -------------(ii)

where;

k = constant = ρ/L

From equation (ii);

The resistance is directly proportional to length. i.e when the resistance increases, the length will also increase and vice-versa. This can be written as follows;

= k

This implies that;

=         -------------------(iii)

Where;

and are the initial values of the resistance and length respectively

and are the final values of the resistance and lenght respectively.

From the question;

= 4.00Ω

= 8.00m

= 16.00m

Substitute these values into equation(iii) as follows;

=

Cross multiply;

4.00 x 16.00 = x 8.00

64.00 = 8.00

Solve for ;

= 64.00/ 8.00

= 8.00Ω

Therefore the resistance of the wire after it has been stretched is 8.00Ω

the displacement produced by the body.  

the amount of force subjected to the body.  

the angle between the direction of force and displacement

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles