<span>velocity is defined as the rate of change of displacement irrespective of the length of the path travelled while speed is the average rate of covering distance. but in the liming case where the instantaneous velocity is given as v=dx/dt where dx is the small displacement in a small interval dt, both the speed and velocity have the same magnitude and the direction of velocity is the direction of the tangent to the corresponding displacement-time curve.</span>
Answer:
Micro and radio waves.
Lower energy.
Gamma rays.
Explanation:
The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their respective wavelengths.
Ionising radiation os defined as the energy required of photons of a wave to ionize atoms, causing chemical reactions.
The energy of the wave depends on both the amplitude and the frequency. If the energy of each wavelength is a discrete packet of energy, a high-frequency wave will deliver more of these packets per unit time than a low-frequency wave. In summary, the longer the wavelength, the lower the energy to ionise.
The velocity of a wave is directly proportional to the frequency of that wave.
c = f * lambda
Where,
c = velocity of the wave
f = frequency of the wave = 1/time
Lambda = wavelength.
From the above expression, the longer the wavelength, lambda the shorter the frequency.
Examples of waves with longer wavelengths are, micro and radio waves, while radiations with shorter wavelengths like gamma rays.
Answer: 288.8 m
Explanation:
We have the following data:
is the time it takes to the child to reach the bottom of the slope
is the initial velocity (the child started from rest)
is the angle of the slope
is the length of the slope
Now, the Force exerted on the sled along the ramp is:
(1)
Where 
is the mass of the sled and 
its acceleration
In addition, if we draw a free body diagram of this sled, the force along the ramp will be:
(2)
Where 
is the acceleration due gravity
Then:
(3)
Finding :
(4)
(5)
(6)
Now, we will use the following kinematic equations to find :
(7)
(8)
Where 
is the final velocity
Finding from (7):
(9)
(10)
Substituting (10) in (8):
(11)
Finding :
Compare the initial mass to the final mass.
