Answer:
Explanation:
Work done in lifting the weight once = mgh
= 20 x 9.8 x (1.9+1.7)
= 705.6 J
= 705.6 / 4.2 calorie
= 168 cals
Total energy to be spent = 600 x 10³ cals
No of times weight is required to be lifted
= 600 x 10³ / 168
= 3.57 x 10³ times
Total time to be taken = 2 x 3.57 x 10³
= 7.14 x 10³ s
=119 minutes .
Answer:
what do you mean ???????????
-- The lenses of eyeglasses work because of refraction.
-- A pencil standing in a half-glass of water looks broken because of refraction.
-- The lenses and mirrors in telescopes and microscopes work because of refraction.
-- When the sun is setting and it looks squashed ... shorter and wider than a true circle ... that's caused by refraction of the sunlight through Earth's atmosphere.
Answer:
2 Joules
Explanation:
Kinetic Energy = 1/2 of (Mass x Velocity^2)
Range, Belt.
Just got it right on e,,d,,g,,e