You can find one the picture I send
Lets Anna's age = A
Mr. Goldstein age = G
Mr. Goldstein is 4 times as old as his daughter Anna.
So G= 4A
In 4 years, he will be 3 times as old as Anna
we add 4 with Both their ages
G + 4 = three times of A + 4
G + 4= 3(A + 4)
We know G= 4A, replace it in above equation
4A + 4= 3(A + 4)
4A + 4= 3A + 12
Subtract 3A from both sides
A + 4 = 12
Subtract 4 from both sides
A = 8
So Anna's age = 8 years
Answer:
-24.8 m/s
Step-by-step explanation:
Given:
y₀ = 60 m
y = 40 m
v₀ = 15 m/s
a = -9.8 m/s²
Find: v
There are three constant acceleration equations we can use:
y = y₀ + v₀ t + ½ at²
v = at + v₀
v² = v₀² + 2a(y − y₀)
We aren't given the time, so we need to use the third equation, which is independent of time:
v² = v₀² + 2a(y − y₀)
Plug in the values:
v² = (15 m/s)² + 2(-9.8 m/s²) (40 m − 60 m)
v² = 617 m²/s²
v ≈ ±24.8 m/s
Since the coin is on the way down, the velocity is negative. So v = -24.8 m/s.
