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

Answer:
B)
Explanation:
That the time period of which they stop.
The height of the object will be -5.19 cm
A concave mirror's reflecting surface curves inward and away from the light source. Light is reflected inward to a single focus point via concave mirrors. Concave mirrors, in contrast to convex mirrors, produce a variety of images depending on the object's to the mirror.
Given an object 24.0 cm from a concave mirror creates a virtual image at -33.5 cm. if the image is 7.25 cm tall
So let,
v = Image distance from the mirror = -33.5 cm
u = object distance from the mirror (concave) = 24 cm
hi = Image height = 7.25 cm
h = height of the object = ?
Using below formula to find height of the object
-v/u = hi/h
Putting all value in the formula we get
-(-33.5)/(-24) = 7.25/h
h = -5.19 cm
Therefore the height of the object will be -5.19 cm
Learn more about Concave mirror here:
brainly.com/question/3727024
#SPJ10
Answer:
776.6 w
1.04 hp
Explanation:
given:
Mass, m = 190kg
height change, h = 25m
time elapsed, t = 60 s
acceleration due to gravity, g = 9.81 m/s²
Potential energy required raising 190 kg of water to a height of 25m
= mgh
= 190 x 9.81 x 25
= 46,597.5 J
Power required in 60 s
= Energy required ÷ time elapsed
= 46,597.5 ÷ 60
= 776.6 Watts (Use conversion 1 W = 0.00134102 hp)
= 776.6 w x 0.00134102 hp/w
= 1.04 hp