Initial speed = 2√10 m/s
<h3>Further explanation </h3>
Linear motion consists of 2: constant velocity motion with constant velocity and uniformly accelerated motion with constant acceleration
An equation of uniformly accelerated motion
V = vo + at
Vt² = vo² + 2a (x-xo)
x = distance on t
vo / vi = initial speed
vt / vf = speed on t / final speed
a = acceleration
vf=20 m/s
d = 60 m
a = 3 m/s²

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:
Both objects will undergo the same change in velocity
Explanation:
m = Mass of the Earth = 5.972 × 10²⁴ kg
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²
r = Radius of Earth = 6371000 m
m = Mass of object
Any object which is falling has only the acceleration due to gravity.

The acceleration due to gravity on Earth is 9.81364 m/s²
So, the speeds of the objects will change at an equal rate of 9.81364 m/s² but the change will be negative when an object is thrown up.
Hence, both objects will undergo the same change in velocity.
Answer:
Explanation:
a)Magnitude = 
84=
x= +50.67 or -50.67 units
b) We are given that the resultant is entirely in the -ve x direction which means that the y-component of the resultant is 0; It means that the y-component of the next vector = -ve of the y component of the initial vector i.e 67.
To make the magnitude 80 units in the negative x direction where the y component is 0, the x component must be -130.67(-50.67 - 80) as the x component is + 50.67units.
Magnitude =
= 146.85 units
c) The direction vector = 67/146.85 i - 130.67/146.85 j where i corresponds to the vector in y direction and j corresponds to the vector in x direction. Or this vector is at an angle of 180 -
i.e 152.85 degrees from the +ve x-axis.