<u>Answer:</u>
Positive acceleration is in third hour and negative acceleration is in second hour.
<u>Explanation:</u>
Velocity of car in first hour = 70 mph
Velocity of car in second hour = 60 mph
Velocity of car in third hour = 80 mph
Acceleration = Change in velocity / Time
Acceleration in second hour = (60 - 70)/1 = -10 mph²
Acceleration in third hour = (80 - 60)/1 = 20 mph²
So positive acceleration is in third hour and negative acceleration is in second hour.
The first thing you should know to answer this question is the following conversion:
1mi = 5280feet
We have then that the speed is:
v = ((1/4) * (5280)) / (8.96)
v = 147.32 feet / s
Answer:
the car's velocity (in ft / s) at the finish line is 147.32 feet / s
Answer:
The magnitude of the electric field is 0.1108 N/C
Explanation:
Given;
number of electrons, e = 8.05 x 10⁶
length of the wire, L = 1.03 m
distance of the field from the center of the wire, r = 0.201 m
Charge of the electron;
Q = (1.602 x 10⁻¹⁹ C/e) x (8.05 x 10⁶ e)
Q = 1.2896 x 10⁻¹² C
Linear charge density;
λ = Q / L
λ = (1.2896 x 10⁻¹² C) / (1.03 m)
λ = 1.252 x 10⁻¹² C/m
The magnitude of electric field at r = 0.201 m;

Therefore, the magnitude of the electric field is 0.1108 N/C