Using a pulley system a worker does 1920 J of work to lift a crate 40 m. How much force was used to lift the crate?

see earlier answer

answerscientific theory;

the best answer for these questions would be:

1.            c. is smaller

2.            d) concrete operational

3.            b) interaction with the environment – the children interact with their environment can them learn more.

4.            a) parents who reason openly with children can limit a child’s cognitive ability.