Where are the statements?
Lower resistivity means higher conductivity: among these materials, the best conductor is silver, therefore it must be the material with lowest resistivity among those. We can also have a look at the value of resistivity of the different materials listed in the problem, to check our answer. The resistivities of the materials are the following:
Wood:

Salt water:

Silver:

Lead:

<span>We see that the material with lowest resistivity among those is silver, therefore the correct answer is silver.</span>
Answer:
a)0.22 m/s².
Explanation:
Given that
Net force ,F= 6.8 N
mass ,m = 31 kg
From the second law of Newton's
F = m a ---------------1
Where
F=Net force ,m=mass
a=Acceleration
Now by putting the values in the equation 1
F = m a
6.8 = 31 x a



Therefore the acceleration of the scooter will be 0.22 m/s².
The answer will be "a".
a)0.22 m/s².
I'm pretty sure it's B
I hope that helps
Period: Time it takes to complete a cycle, it takes 0.5s to complete a cycle
Frequency: Number of cycles in a second. Since 0.5s = 1 cycle, 1s=2 cycles
Period is 0.5s, frequency is 2