Pretty sure the answer is   C. Screw: wheel and axle
 
        
             
        
        
        
Answer:
2361.6N
Explanation:
Mass of player = 82kg
Velocity = 1.2m/s
Kinetic energy of player:
= 1/2mv²
= 1/2*82*1.2²
= 41x1.44
= 59.04J
Final kinetic energy = 0
Change in kinetic energy
|∆k| = |0-59.04|
= 59.04
Workdone by the feet = fd
d = 0.025
Fd = 59.04
F = 59.04/0.025
= 2361.6N
This is his average force.
 
        
             
        
        
        
Answer:
Its d
 atome contain 
negative electrons, 
positive protons and uncharged neutrons.
Explanation:
 
        
             
        
        
        
An element refers to a collection of atoms having the same number of protons and electrons (an atomic number). In each element there is a different atomic number due to a different amount of protons in the nucleus. 
An isotope is a variation of an element that contains a different number of neutrons, therefore adding weight to the atom. 
An ion is a charged atom, and its charge shows how many electrons it needs to gain or lose in order to become stable.
        
             
        
        
        
This question is incomplete, the complete question is;
Two plane mirrors intersect at right angles. A laser beam strikes the first of them at a point 11.5 cm from their point of intersection, as shown in the figure.
For what angle of incidence at the first mirror will this ray strike the midpoint of the second mirror (which is 28.0 cmcm long) after reflecting from the first mirror
Answer: angle of incidence is 39.4°
Explanation:
Given that;
two plain mirrors intersect at right angle (90°)
distance d = 11.5 cm
S = 28.0 cm
Now the angle that the reflection ray males with first the mirror equal theta  (∅)
so
tan∅ = (S/2) / d
tan∅ = (28/2) / 11.5
tan∅ = 14 / 11.5 
tan∅ = 1.2173
∅ = tan⁻¹ (1.2173)
∅ = 50.6°
so angle of incidence = 90° - ∅
= 90° - 50.6°
= 39.4°
Therefore angle of incidence is 39.4°