Explanation:
Given that,
Initial speed of the car, u = 88 km/h = 24.44 m/s
Reaction time, t = 2 s
Distance covered during this time, 
(a) Acceleration, 
We need to find the stopping distance, v = 0. It can be calculated using the third equation of motion as :
s = 74.66 meters
s = 74.66 + 48.88 = 123.54 meters
(b) Acceleration, 
s = 37.33 meters
s = 37.33 + 48.88 = 86.21 meters
Hence, this is the required solution.
Answer:
k = 1.30
Explanation:
For this exercise let's write the capacitance in air and with dielectric
air C₀ = Q / DV
dielectric C = k Q / DV
They tell us that the capacitor is charged and then the battery is disconnected, therefore the charge stored on the plate remains constant.
therefore the capacitance a changes to the value
C = k C₀
The voltage in the presence of dielectric must meet the relationship
ΔV = ΔV₀ / k
k = ΔV₀ /ΔV
let's calculate
k = 60/46
k = 1.30
