Answer:
5.41 days
Explanation:
To find the number of days you use the decay law for radioactivity:
No: initial amount of 139np
T1/2: half-life = 2.35 days
after the decat, the final amount is 0.100% of the initial 239np, that is N=0.1No. Hence, you have:
by applying properties of logarithms you obtain:
hence, the number of days is 5.41 days
Answer:
value of L = 4.75 cm
Explanation:
given data
capacitor = 100 pF = 100 × F
thick = 0.20 mm = 2 × m
solution
we get here area of each plate that is
area = L² .......................1
and
Capacitance, C = εo A ÷ d ..................2
put here value so we get
100 × = 8.854 × × L² ÷ ( 2 × )
solve it and we will get
L = 0.047528 m
value of L = 4.75 cm
Answer:
Explanation:
From the information given;
mass of the crate m = 41 kg
constant horizontal force = 135 N
where;
coefficient of kinetic friction = 0.28
a)
To start with the work done by the applied force
Work done by friction:
Work done by gravity:
Work done by normal force;
b)
total work by all forces:
W = 2100.5 J
c) By applying the work-energy theorem;
total work done = ΔK.E
Answer:
Loam is 40% sand, 40% silt, and 20% clay
Explanation:
Explanation:
Second question:
U
=
I
2
×
R
2
=
4
A
×
9
Ω
=
36
V
First question:
You could use
1
R
=
1
R
1
+
1
R
2
+
1
R
3
=
1
18
+
1
9
+
1
6
=
1
3
→
R
=
3
Ω
Or:
You can calculate the currents through the other resistors, add them all up and recalculate the total resistance (voltage already calculated):
I
1
=
U
R
1
=
36
V
18
Ω
=
2
A
I
2
=
4
A
(as given)
I
3
=
U
R
3
=
36
V
6
Ω
=
6
A
Now
R
=
U
I
=
36
V
2
A
+
4
A
+
6
A
=
36
V
12
A
=
3
Ω