Data:
h=25 m
v₀=0 m/s
g=9,8 m/s²
we use this formula
h=h₀+v₀.t+(1/2).g.t²
25 m=0 m+0 m/s.t+(1/2).(9,8 m/s²).t²
25 m=4,9 m/s².t²
t²=25 m /4,9 m/s²
t²=5,1 s²
t=√(5,1 s²)=2,26 s
Now, we calculate the última velocity
v=v₀+gt
v=0 m/s+9,8 m/s².(2,26 s)=22,14 m/s≈22 m/s
solution: c.) 22 m/s
Answer: 4 ohms
Explanation:
For parallel connection we use this formula
R=equivalent resistance
R1=24 ohms
R2=8 ohms
R3=12 ohms
1/R=1/R1 + 1/R2 + 1/R3
1/R=1/24 + 1/8 + 1/12
1/R=(1x1+3x1+2x1) ➗ 24
Cross multiplying we get
24x1=(1x1+3x1+2x1) x R
24=(1+3+2) x R
24=6xR
Divide both sides by 6
24 ➗ 6=6xR ➗ 6
4=R
R=4 ohms