Answer:
The driver's average velocity is 82.35 km/h.
Explanation:
Given:
The motion of the driver can be divided into 3 parts:
i. Displacement of the driver in 1.5 hours = 135 km
ii. Rest for 45 minutes.
iii. Displacement in next 2 hours = 215 km
The direction of motion remains same (east).
Now, total displacement of the driver is, 
km.
Rest time is 45 minutes. Converting it to hours, we need to use the conversion factor 
hour.
So, 45 minutes in hours is equal to 
hours.
Now, total time taken for the complete journey is, 
Average velocity is given as:
Therefore, the driver's average velocity is 82.35 km/h
Explanation:
Since compasses work by pointing along magnetic field lines, this means that there must be a magnetic field near the wire through which the current is flowing.
Answer:
E_interior = 0
Explanation:
As the sphere is metallic, the electrical charges are distributed on its surface, as far away as possible from each other.
If we apply Gauss's law, as the charge is on the surface, when drawing a spherical Gaussian surface, we see that there is no charge inside, therefore there is no electric field inside the metallic sphere.
E_interior = 0
A scientist can assess whether a pure niobium sample is responsible for contaminating the lab with radioactivity by testing the sample. By testing the niobium sample, a scientist can determine whether it has any other element.
High frequency = D, short wavelength
