Answer:
b) 2ft/s
Explanation:
A scalar has only magintude, not direction
6.2m, 3kg, and -100 o C are all scalars because they only have magnitude.
2ft/s is not a scalar because it has a direction.
Answer:
(a) 23.946 kV
(b) -0.077 J
Explanation:
(a) The electric potential is given by the following formula:
(1)
k: Coulomb's constant = 8.98*10^9 Nm^2/C^2
q1 = q2 = 1.60*10^{-6}C
r1 and r2 are the distance from the charges to the point in which electric potential is evaluated.
Firs, you calculate the distance r1 and r2 by taking into account the position of the charges

Next, you replace the values of the parameters to calculate V:

(b) The potential electric energy is given by:
![U_T=U_{1,2}+U_{1,3}+U_{2,3}\\\\U_T=k\frac{q_1q_2}{r_{1,2}}+k\frac{q_1q_3}{r_{1,3}}+k\frac{q_2q_3}{r_{2,3}}\\\\r_{1,2}=2.00m\\\\r_{1,3}=1.20m\\\\r_{2,3}=1.20m\\\\U_T=(8.98*10^9)[\frac{(1.6*10^{-6})^2}{2.00m}+\frac{(1.6*10^{-6})(-3.70*10^{-6})}{1.20}+\frac{(1.6*10^{-6})(-3.70*10^{-6})}{1.20}]J\\\\U_T=-0.077J](https://tex.z-dn.net/?f=U_T%3DU_%7B1%2C2%7D%2BU_%7B1%2C3%7D%2BU_%7B2%2C3%7D%5C%5C%5C%5CU_T%3Dk%5Cfrac%7Bq_1q_2%7D%7Br_%7B1%2C2%7D%7D%2Bk%5Cfrac%7Bq_1q_3%7D%7Br_%7B1%2C3%7D%7D%2Bk%5Cfrac%7Bq_2q_3%7D%7Br_%7B2%2C3%7D%7D%5C%5C%5C%5Cr_%7B1%2C2%7D%3D2.00m%5C%5C%5C%5Cr_%7B1%2C3%7D%3D1.20m%5C%5C%5C%5Cr_%7B2%2C3%7D%3D1.20m%5C%5C%5C%5CU_T%3D%288.98%2A10%5E9%29%5B%5Cfrac%7B%281.6%2A10%5E%7B-6%7D%29%5E2%7D%7B2.00m%7D%2B%5Cfrac%7B%281.6%2A10%5E%7B-6%7D%29%28-3.70%2A10%5E%7B-6%7D%29%7D%7B1.20%7D%2B%5Cfrac%7B%281.6%2A10%5E%7B-6%7D%29%28-3.70%2A10%5E%7B-6%7D%29%7D%7B1.20%7D%5DJ%5C%5C%5C%5CU_T%3D-0.077J)
By using the equation speed = distance/time we can solve for distance. The speed is 4 m/s and the time is 12 seconds. We need to rearrange the equation to Speed * Time = distance. 4(12) = 48; 48 = distance. The cliff is 48 meters high.