Answer:
she must increase the current by factor of 7
Explanation:
The magnetic field produced by a steady current flowing in a very long straight wire encircles the wire.In order to solve the question, we use this formula,
B= μo I/(2πr)
where,
'μo' represents permeability of free space i.e 4π*10-7 N/A2
B=magnetic field
I= current
r=radius
->When r= 1cm=> 0.01m
B1 = μo
/(2π x 0.01)
->when r=7cm =>0.07m
B2 = μo
/(2π x 0.07)
Now equating both of the magnetic fields, we have
B1= B2
μo
/(2π x 0.01)= μo
/(2π x 0.07)
/
= 0.01/0.07
/
= 1/ 7
Therefore, she must increase the current by factor of 7
Answer:
7.81 m/s
Explanation:
Given,
initial speed, u = 10.2 m/s
angle of inclination, θ = 40°
time, t = 2.12 s
Horizontal component of the velocity:



In projectile motion horizontal component of the velocity remain same at every point because there is no acceleration.
So, Velocity at the Pinnacle is equal to 7.81 m/s
Given: distance 1 d₁ = 40 m; distance 2 d₂ = 3.8 m g = -9.8 m/s²
Initial Velocity Vi = 0 Final Velocity of stone 2 is unknown = ?
Total distance dₓ = d₁ - d₂ = 40 m - 3.8 m = 36.2 m
Formula: a = Vf² - Vi²/2d derive for Final Velocity Vf
acceleration is now due to gravity, therefore a = g
Vf = √2gd Vf = √2(9.8 m/s²)(36.2 m)
Vf = 26.64 m/s
Reason: The second stone will still start from rest.
Answer:
the terminal velocity of 14 nested coffee filters is 3.2 m/s
Explanation:
Given the data in the question;
we know that;
The terminal velocity is proportional to the square root of weight.
v ∝ √W
v = k√W
the proportionality constant depends upon the surface area and the density of the medium (like air). The coffee filters can be stacked such that the resulting area is roughly unchanged. So, the constant of proportionality k is also unchanged
v/√W = constant
v₂/√W₂ = v₁/√W₁
v₂ = v₁√(W₂ / W₁ )
given that;
v₁ = 0.856 m/s,
W₂ = 14W₁; meaning 14 coffee filters have 14 times the weight of a single coffee filter
so we substitute
v₂ = 0.856 √(14W₁ / W₁ )
v₂ = 0.856 √( 14( W₁/W₁)
v₂ = 0.856 √( 14(1)
v₂ = 0.856 √( 14 )
v₂ = 0.856 × 3.741657
v₂ = 3.2 m/s
Therefore, the terminal velocity of 14 nested coffee filters is 3.2 m/s
Answer:
The ball doesn't strike the building because it strikes the ground at d=1.62 meters.
Explanation:
V= 5 m/s < 70º
Vx= 1.71 m/s
Vy= 4.69 m/s
h= Vy * t - g * t²/2
clearing t for the flying time of the ball:
t= 0.95 s
d= Vx * t
d= 1.62 m