Answer: A... Thermal energy from the ice is transferred to the air.
Explanation: because I just know.
The only vertical forces are weight and normal force, and they balance since the surface is horizontal. The horizontal forces are the applied force (uppercase F) in the direction the block slides and the frictional force (lowercase f) in the opposite direction.
Apply Newton's 2nd Law in the horizontal direction:
ΣF = ma
F - f = ma
where f = µmg
F - µmg = ma
F = m(a +µg)
F = (20 kg)(1.4 m/s² + 0.28(9.8 m/s²)
F = 83 N
A nitrogen laser generates a pulse containing 10.0 mj of energy at a wavelength of 340.0 nm and has 1785 x 10¹⁹ photons in the pulse.
<h3>How many photons are in the pulse?</h3>
Energy of a single photon is
E=hcλ
E=6.626×10⁻³⁴ J s×3×108 m/s /340×10⁻⁹ m
E=6.31×10⁻¹⁹ J
Number of photons in the laser is
n=Total Energy/Energy per photon
n=10⁷×10⁻³J /5.90×10⁻¹⁹J/photon
n= 1785 x 10¹⁹ photons
To learn about photons, refer: brainly.com/question/20912241?referrer=searchResults
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