Answer:
Explanation:
Given
Initial speed of ball 
Launch angle 
As there is no acceleration in horizontal direction therefore there is no change in velocity
thus horizontal velocity remains unchanged



Time of flight of projectile is



Thus time for which it is in air is 2.12 s
Answer: 1.4mi/hr²
Explanation:
Blank 1: We know that acceleration is the change in velocity/change in time
Using this, we know that the acceleration will be: (50-15)/25 = 1.4
Blank 2: mi/hr²
They are identically equivalent. Indeed, current research seeks to confirm that they are one and the same
Answer:
t = 39.04 1010 year
Explanation:
This is a nuclear disintegration exercise that is governed by the equation.
N = N0 e (-lam t)
The average life time is related to nuclear activity
T ½ = ln 2 / lam
Let's use these two equations for exercise, let's start by finding nuclear activity
Lam = ln 2 / T ½
Lam = ln 2 / 4.9 10 10
Lam = 0.14146 10-10 y-1
They tell us that the relationship atoms
No / N = 0.0040
Let's look
No / N = 1/0040
N/No = 250
Let's calculate the time
(-lam t) = ln (N / No)
, t = - 1 / lam ln (n / No)
t = - 1 / 0.14146 10-10 ln (250)
t = 39.04 1010 year
Answer: Not 100% sure but I believe the answer is B.
Hope this helps! ^^