Answer:
69.68 N
Explanation:
Work done is equal to change in kinetic energy
W = ΔK = Kf - Ki = 
W = 
where m = mass of the sprinter
vf = final velocity
vi = initial velocity
W = workdone
kf = final kinetic energy
ki = initial kinetic energy
d = distance traveled
Ftotal = total force
vf = 8m/s
vi= 2m/s
d = 25m
m = 60kg
inserting parameters to get:
W = ΔK = Kf - Ki = 



= 39.7
we know that the force the sprinter exerted F sprinter, the force of the headwind Fwind = 30N

The average acceleration can be found by dividing the final speed by the time taken to reach said point so in this case you divide 60 by 8 resulting in 7.5 which will be your answer
D. <span>Johannes Kepler argued that Earth was the center of the universe.
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Answer:
m = 14*26 = 364
Explanation:
overall magnification is given as m

mo magnification of objective lens
me magnification of EYE lens
where mo is given as

and me as

d is distant of distinct vision = 25.0 cm for normal eye
fe = focal length of eye piece
focal length of objective lense is 0.140 cm
we know that








m = 14*26 = 364
Answer:
Explanation:
Let the resistance of resistor be R .
Power of resistor V² / R , where V is potential applied .
V² / R = 100
120² / R = 100
R = 120² / 100
= 144 ohm .
Now potential diff applied = 220 V
current = potential diff / resistance
= 220 / 144
= 1.53 A approx .