The pulley is really a wheel and axle with a rope or chain attached. A pulley makes work seem easier because it changes the direction of motion to work with gravity. Let's say you have to lift a heavy load, like a bale of hay, up to the second floor of a barn. You could tie a rope to the bale of hay, stand on the second floor, and pull it straight up. Or you could put a pulley at the second floor, stand at the first floor, and lift the bale of hay by pulling straight down. It would be the exact amount of work in either case, but the action of pulling down feels easier because you're working with the force of gravity.
A pulley really saves effort when you have more than one pulley working together. By looping a rope around two, three, or even four pulleys, you can really cut down on the effort needed to lift something. The trade-off? Well, as you increase the number of pulleys, you also increase the distance you have to pull the rope. In other words, if you use two pulleys, it takes half the effort to lift something, but you have to pull the rope twice as far. Three pulleys will result in one-third the effort — but the distance you have to pull the rope is tripled!
Answer:
Explanation: work equals force times distance so 400x4=1600 joules
Explanation:
It is given that,
Density of asteroid, 
Mass of asteroid, 
We need to find the diameter of the asteroid. The formula of density is given by:
V is the volume of spherical shaped asteroid, 
r = 2441311.12 m
Diameter = 2 × radius
d = 4882622.24 m
or
Hence, this is the required solution.
Answer:
If the population were to INCREASE land use would also INCREASE, if the human population DECREASED so would land use because there wouldn’t be as many people to using it. hope i helped
