1 hour = 3600 seconds.
Energy dissipated = I²Rt = 8²×20×3600 = 4608000 J
Answer:
Explanation:
initial momentum = .36 kg.m.s⁻¹
negative impulse = force x time = .02 x 12 = .24 kg.m.s⁻¹
final momentum - initial momentum = impulse
final momentum = initial momentum + impulse
= .36 - .24
= .12 kg.m.s⁻¹
Given that,
Frequency emitted by the bat, f = 47.6 kHz
The speed off sound in air, v = 413 m/s
We need to find the wavelength detected by the bat. The speed of a wave is given by formula as follows :
or
So, the bat can detect small objects such as an insect whose size is approximately equal to the wavelength of the sound the bat makes i.e. 8.67 mm.
Answer:
T = 480.2N
Explanation:
In order to find the required force, you take into account that the sum of forces must be equal to zero if the object has a constant speed.
The forces on the boxes are:
(1)
T: tension of the rope
M: mass of the boxes 0= 49kg
g: gravitational acceleration = 9.8m/s^2
The pulley is frictionless, then, you can assume that the tension of the rope T, is equal to the force that the woman makes.
By using the equation (1) you obtain:
The woman needs to pull the rope at 480.2N
-- Equations #2 and #6 are both the same equation,
and are both correct.
-- If you divide each side by 'wavelength', you get Equation #4,
which is also correct.
-- If you divide each side by 'frequency', you get Equation #3,
which is also correct.
With some work, you can rearrange this one and use it to calculate
frequency.
Summary:
-- Equations #2, #3, #4, and #6 are all correct statements,
and can be used to find frequency.
-- Equations #1 and #5 are incorrect statements.