Answer:
32 bottles
Explanation:
If we create a free body diagram on the child we have his weight and the bouyant force
W-B=0
They must be equal to mantain equilibrium on the body and he can stay floating, this force is equivalent to the weight of water displaced
W=B=Ww
Mg=mg
32 kg=mass of water displaced
1 kilogram per liter (kg/L) is the density of water, this means that 32 Liters of water are displaced and since the bottles can retain 1 liter, the child needs 32 bottles
Answer:
Explanation:
Given:
- Three identical charges q.
- Two charges on x - axis separated by distance a about origin
- One on y-axis
- All three charges are vertices
Find:
- Find an expression for the electric field at points on the y-axis above the uppermost charge.
- Show that the working reduces to point charge when y >> a.
Solution
- Take a variable distance y above the top most charge.
- Then compute the distance from charges on the axis to the variable distance y:
- Then compute the angle that Force makes with the y axis:
cos(Q) = sqrt(3)*a / 2*r
- The net force due to two charges on x-axis, the vertical components from these two charges are same and directed above:
F_1,2 = 2*F_x*cos(Q)
- The total net force would be:
F_net = F_1,2 + kq / y^2
- Hence,
- Now for the limit y >>a:
- Insert limit i.e a/y = 0
Hence the Electric Field is off a point charge of magnitude 3q.
law of conservation of energy
aka the first law of thermodynamics
Answer:
a) r = 6122 m and b) v = 32.5 m / s
Explanation:
a) The train in the curve is subject to centripetal acceleration
a = v2 / r
Where v is The speed and r the radius of the curve
They indicate that the maximum acceleration of the person is 0.060g,
a = 0.060 g
a = 0.060 9.8
a = 0.588 m /s²
Let's calculate the radius
v = 216 km / h (1000m / 1km) (1 h / 3600 s =
v = 60 m / s
r = v² / a
r = 60² /0.588
r = 6122 m
b) Let's calculate the speed, for a radius curve 1.80 km = 1800 m
v = √a r
v = √( 0.588 1800)
v = 32.5 m / s
Answer:
C. it will not change.
Explanation:
While combing, the rubbing of the comb with the hair, transfer of electron takes place from the hair to the comb and the comb becomes negatively charged. But, this transfer of electron does not make any considerable change in the mass of the hair. This is because the mass of an electron is highly negligible. Now, neglecting the mass of an electron, the transfer of the electrons from the hair to the comb makes charging of the comb, but no loss of mass in the hair. So, the mass of hair will no change.
