Answer:
It would take the object 5.4 s to reach the ground.
Explanation:
Hi there!
The equation of the height of a free-falling object at any given time, neglecting air resistance, is the following:
h = h0 + v0 · t + 1/2 · g · t²
Where:
h = height of the object at time t.
h0 = initial height.
v0 = initial velocity.
g = acceleration due to gravity (-32.2 ft/s² considering the upward direction as positive).
t = time
Let´s supose that the object is dropped and not thrown so that v0 = 0. Then:
h = h0 + 1/2 · g · t²
We have to find the time at which h = 0:
0 = 470 ft - 1/2 · 32.2 ft/s² · t²
Solving for t:
-470 ft = -16.1 ft/s² · t²
-470 ft / -16.1 ft/s² = t²
t = 5.4 s
Answer:
(a) 272.73 m
(b) 0.338 N/C
Explanation:
frequency, f = 1100 kHz = 1100 x 1000 Hz
E(t) = Eo Sin(2πft)
Eo = 0.62 N/C
(a) Velocity of light, c = 3 x 10^8 m/s
wavelength, λ = c / f = (3 x 10^8) / (1100000) = 272.73 m
Thus, the wavelength is 272.73 m.
(b) at t = 3.1 microsecond = 3.1 x 10^-6 s
E = Eo Sin (2 π ft)
E = 0.62 Sin (2 x 3.14 x 1100 x 10^3 x 3.1 x 10^-6)
E = 0.62 Sin (21.4148)
E = 0.62 x 0.5449 = 0.338 N/C
Thus, the electric field at t = 3.1 microsecond s 0.338 N/C.
<h2>The emf produced is 7.2 V</h2>
Explanation:
When coil is placed in the magnetic field , the flux attached with it can be found by the relation . Flux Ф = the dot product of magnetic field and area of coil .
Thus Ф = B A cosθ
here B is magnetic field strength and A is the area of coil .
The angle θ is the angle between coil and field direction .
When coil rotates , the angle varies . By which the flux varies . The emf is produced in coil due to variation of flux . The relation for this is
The emf produced ξ = - 
= B A sinθ 
Now in the given problem
5 = 0.38 x A x I
Now if the magnetic field is 0.55 T and all the other terms are same , the emf produced
ξ = 0.55 x A x Ii
dividing II by I , we have
= 
= 1.45
or ξ = 7.2 V
Answer:
Explanation:
weight of woman acting downwards = 90 x 10 = 900 N
force by bungee cord in upward direction = 500 N
net force = 900 - 500 = 400 N in downward direction
acceleration in downward direction
= 400 / 90
= 4.44 m /s²
