What are the mechanical advantage and mechanical efficiency of a lever that requires an input force of 40 N and lifts and lifts a boulder that weighs 80 N?

2 , 200%

Explanation:

Mechanical advantage of a machine is defined as how much the machine multiplies the applied force.

It is given that :

Input force of the lever = 40 N

The weight of the boulder or the output force = 80 N

Therefore, the mechanical advantage = output force / input force

                                                               = 2

Mechanical efficiency is obtained by the dividing the output by the input and multiplying it with 100.

i.e. Efficiency = output / input x 100

                     = 200 %

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.