Answer:
C
Sign-Negative
Explanation:
We are given that
Electric field =
(Radially downward)
Acceleration=
(Upward)
Mass of charge=3 g=
kg
1kg=1000g
We have to find the magnitude and sign of charge would have to be placed on a penny .
By newton's second law


Substitute the values then we get

Substitute the values then we get




C
Sign of charge =Negative
Because electric force acting in opposite direction of electric field therefore,charge on penny will be negative.
Answer
given,
number of dog = 8
mass of each dog= 19 Kg
mass of sled = 210 Kg
average force = 185 Nss
a) writing all the horizontal force
force acting by dog - friction force = (M + 8m) a
8 F_d - μ m g = (M + 8m) a
assuming coefficient of friction of snow be μ = 0.14
8 x 185 - 0.14 x 210 x 9.8 = (210 + 8 x 19 ) x a
a = 3.29 m/s²
b) the kinetic friction of coefficient is less than static friction
hence, we can suggest that acceleration of the sled will increase once the sled start to move.
a > 3.29 m/s²
Answer:
Electrolysis is the process by which ionic substances are decomposed (broken down) into simpler substances when an electric current is passed through them. ... Electricity is the flow of electrons or ions. For electrolysis to work, the compound must contain ions.