True, they represent the direction of motion
Answer:
108 extended days
Explanation:
Regular school hours a day = 6 hr
No. of school days to make up by extending the regular hours = 3 days
Amount of time added to the regular hours of school = 10 min
No. of extended school days to make up the 3 school days by following the above mentioned criteria be x.
Time of school hours in 3 days = 

are required to make up 3 days of school having 6 hours of regular timing with 10 minutes of add-on time each day.
Answer:
T/√8
Explanation:
From Kepler's law, T² ∝ R³ where T = period of planet and R = radius of planet.
For planet A, period = T and radius = 2R.
For planet B, period = T' and radius = R.
So, T²/R³ = k
So, T²/(2R)³ = T'²/R³
T'² = T²R³/(2R)³
T'² = T²/8
T' = T/√8
So, the number of hours it takes Planet B to complete one revolution around the star is T/√8
Answer:
y₀ = 10.625 m
Explanation:
For this exercise we will use the kinematic relations, where the upward direction is positive.
y = y₀ + v₀ t - ½ g t²
in the exercise they indicate the initial velocity v₀ = 8 m / s.
when the rock reaches the ground its height is zero
0 = y₀ + v₀ t - ½ g t²
y₀i = -v₀ t + ½ g t²
let's calculate
y₀ = - 8 2.5 + ½ 9.8 2.5²
y₀ = 10.625 m