Answer: Because of the friction force acting directly on the bag.
Explanation:
The function of the wheels is diminish the effect of the friction force, when the friction pulls back, it makes the wheel rotate, and this force is not applied directly on the bag.
Now the wheels are not working, so now the friction is acting directly on the bag, this is why the mand finds more difficult to drag the bag.
Answer:
The magnetic field strength, the energy density, and the power flow per unit area are , and 13.18 W/m².
Explanation:
Given that,
Electromagnetic wave strength E= 70.5 V/m
(I). We need to calculate the magnetic field strength
Using formula of Electromagnetic wave strength
(II). We need to calculate the energy density
Using formula of energy density
(III). We need to calculate the power flow per unit area
Using formula of poynting vector
Put the value into the formula
Hence, The magnetic field strength, the energy density, and the power flow per unit area are , and 13.18 W/m².
1) Frequency:
the energy of the photon absorbed must be equal to the ionization enegy of the atom, which is
The energy of a photon is given by
where is the Planck's constant. By using the energy written above and by re-arranging thsi formula, we can calculate the frequency of the photon:
2) Wavelength: 91.2 nm
The wavelength of the photon can be found from its frequency, by using the following relationship:
where is the speed of light and f is the frequency. Substituting the frequency, we find
Answer:
a) F = 527.65 N, Force applied is upwards.
b)F = - 527.65 N, where, negative sign depicts Force is applied downwards.
Explanation:
Data provided:
Weight of the firefighter = 756 N
Mass of the firefighter = 756/9.8 = 77.14 Kg
Acceleration, a = 2.96 m/s²
a) In the absence of the pole the firefighter would have been moving down with an acceleration of 9.8 m/s (i.e the acceleration due to the gravity), but due to the presence of the pole the acceleration of the firefighter has been reduced. thus, a force is applied by the pole on the firefighter to reduce the acceleration.
therefore, we have
F = ma(net) = 77.14 × (9.8-2.96) = 527.65 N, Force applied is upwards.
B) According to the Newton's third law, the force will be equal and opposite to the force in the part a)
thus, we have
F = - 527.65 N
The average velocity is obtained by ( u + v)/2.
<h3>What is average velocity?</h3>
The term velocity refers to the rate of change of displacement with time. Velocity is a vector quantity thus it has both magnitude and direction. The velocity of a body could also be shown by the use of the vector notation.
To obtain the average velocity;
Let the initial velocity be u
Let the final velocity be v
It then follows that the average velocity = ( u + v)/2
Learn more about average velocity:brainly.com/question/862972
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