Answer:
Ro = 7.8 [g/cm³]
Explanation:
According to the principle of Archimedes, the volume of a body immersed in a liquid is equal to the volume displaced by water. That is, in this problem The displacement volume is equal to the new volume minus the original volume.
![V_{n}=110[cm^{3} ]\\V_{o}=100[cm^{3} ]\\V_{d}=110-100 = 10 [cm^{3} ]](https://tex.z-dn.net/?f=V_%7Bn%7D%3D110%5Bcm%5E%7B3%7D%20%5D%5C%5CV_%7Bo%7D%3D100%5Bcm%5E%7B3%7D%20%5D%5C%5CV_%7Bd%7D%3D110-100%20%3D%2010%20%5Bcm%5E%7B3%7D%20%5D)
We now know that density is defined as the relationship between mass and volume.

where:
Ro = density [g/cm³]
m = mass = 78 [g]
Vd = displacement volume [cm³]
![Ro = 78/10\\Ro = 7.8 [g/cm^{3} ]](https://tex.z-dn.net/?f=Ro%20%3D%2078%2F10%5C%5CRo%20%3D%207.8%20%5Bg%2Fcm%5E%7B3%7D%20%5D)
Answer:
a) 
b) 
c) 
Explanation:
Given:
- voltage of the battery,

- energy storage capacity of the battery,

- speed of the car,

a)
power drawn by the car, 
<u>Now the Current delivered to the motor:</u>
we the relation between the power and electrical current,



b)
<u>Distance travelled before battery is out of juice:</u>
we first find the time before the battery runs out,



Now the distance:



c)
When the head light of 55 W power is kept on while moving then the power consumption of the car is:



<u>Now the time of operation of the car:</u>



<u>Now the distance travelled:</u>



Answer:
The magnetic field strength due to current flowing in the wire is9.322 x 10⁻⁶ T.
Explanation:
Given;
electric current, I = 21.3 A
distance of the magnetic field from the wire, R = 45.7 cm = 0.457 m
The strength of the resulting magnetic field at the given distance is calculated as;

Where;
μ₀ is permeability of free space = 4π x 10⁻⁷ T.m/A

Therefore, the magnetic field strength due to current flowing in the wire is 9.322 x 10⁻⁶ T.