All of the above. They all right
<h3>It takes 60 seconds to do the work</h3>
<em><u>Solution:</u></em>
Given that,
Force = 100 newtons
Distance = 15 meters
Power = 25 watts
To find: time it takes to do the work
<em><u>Find the work done:</u></em>

<em><u>Find the time taken</u></em>

Thus it takes 60 seconds to do the work
Answer:
a)
s
b) 3.41 mm
Explanation:
a)
We take the speed of light, c =
m/s and the refractive index of glass as 1.517.
Speed = distance/time
Time = distance/speed
Refractive index, n = speed of light in vacuum / speed of light in medium






b)
We take the refractive index of water as 1.333.
Speed in water = speed in vacuum / refractive index of water
Distance = speed * time



d = 3.41 mm
Answer:
1. 75N
2. 67,983 J (=67.98 kJ)
Explanation:
1. Work = Force x Distance
we are given that Work = 1,500J and Distance = 20m
hence,
Work = Force x Distance
1,500 = Force x 20
Force = 1,500 ÷ 20 = 75N
2. Potential Energy, PE = mass x gravity x change in height
we are given that mass = 165 kg and change in height = 42m
assuming that gravity, g = 9.81 m/s²
Potential Energy, PE = mass x gravity x change in height
Potential Energy, PE = 165 x 9.81 x 42 = 67,983 J (=67.98 kJ)