Use Factor-Label Method:
8miles 63360 inches
---------- X --------------------- X
1 1 mile
2.54cm 1 meter
X ------------ X ---------------- X
1 inch 100 cm
1 km
----------------- = 12.87 km
1000meters
8 miles = 12.87 km
F = q₁q₂C / r²
F force
q charge
C Coulomb constant
r separation between charges
Answer:
Lithium and Sodium
Explanation:
Lithium and Sodium is in the same group 1A
90 F = 43 OR 0.9F = 0.43
(F = 43 / 90 OR 0.43 / 0.9 =) 0.48 N
upwards force = downwards force
(R =) 1.2 N