Reflection: you look in the mirror.
Refraction: You put a straw in a glass of water, and it looks like it broke.
Absorption: If you have a black sweater and you wear it out in the cold, the black sweater is going to hold in heat better than a lighter sweater because the black sweater absorbs light .
        
             
        
        
        
Answer:
2 seconds
Explanation:
if a ball travels 1/2 meter per second, and there's 2 halfs in a whole, 1/2 meter per second x 2 halfs in a whole meter is 2 seconds to travel a meter
 
        
             
        
        
        
Answer:
a. 7.38 N b. 40.87 N c. 0.113 kg-m²
Explanation:
 
        
             
        
        
        
Answer:
1.10m/s
2.0.1m
3.5Hz
Explanation:
v=velocity, f=frequency and T=wavelength
1.v=ft
 v=2x5
 =10m
2.v=ft
 100=1000T
 divide both sides by 1000
 T=0.1m
3.v=fT
 25=5f
 divide both sides by 5
 f=5Hz
 
        
             
        
        
        
Answer:
the number density of the protons in the beam is 3.2 × 10¹³ m⁻³
Explanation:
 Given that;
diameter D = 2.0 mm
current I = 1.0 mA
K.E of each proton is 20 MeV
the number density of the protons in the beam = ?
Now, we make use of the relation between current and drift velocity
I = MeAv ⇒ 1 / eAv
The kinetic energy of protons is given by;
K = 
 v²
v²
v = √( 2K /  )
 )
lets relate the cross-sectional area A of the beam to its diameter D;
A =  πD²
πD²
now, we substitute for v and A
n = I /  πeD² ×√( 2K /
πeD² ×√( 2K /  )
 )
n = 4I/π eD² × √( / 2K )
 / 2K )
so we plug in our values;
n = ((4×1.0 mA)/(π(1.602×10⁻¹⁹C)(2mm)²) × √(1.673×10⁻²⁷kg / 2×( 20 MeV)(1.602×10⁻¹⁹ J/ev )
n =  1.98695 × 10¹⁸ × 1.6157967  × 10⁻⁵ 
n = 3.2 × 10¹³ m⁻³   
Therefore, the number density of the protons in the beam is 3.2 × 10¹³ m⁻³