A person pushes a box. He applies a force of 400 newtons, and he pushes the box for a distance of 4 meters. After he stops pushing, the box slides forward another meter. How much work was done by the person?(1 point)
Responses
1,600 joules
1,600 joules
2,000 joules
2,000 joules
400 joules
400 joules
100 joules
1,600 joules
Use the diagram of the pulley system to complete the statement.
An illustration shows a system of two pulleys lifting a block.
In this pulley system, the pulleys will _____ the mechanical force required to lift the block and will change the _____.
(1 point)
Responses
increase; weight of the block
increase; weight of the block
increase; direction of the force
increase; direction of the force
decrease; weight of the block
decrease; weight of the block
decrease; direction of the force
increase; direction of the force
Question
Which list correctly orders effort (E), fulcrum (F), and load (L) for each lever class?(1 point)
Responses
class 1 = F, E, L (or L, E, F)
class 2 = F, L, E (or E, L, F)
class 3 = L, F, E (or E, F, L)
class 1 = F, E, L (or L, E, F) class 2 = F, L, E (or E, L, F) class 3 = L, F, E (or E, F, L)
class 1 = F, E, L (or L, E, F)
class 2 = L, F, E (or E, F, L)
class 3 = F, L, E (or E, L, F)
class 1 = F, E, L (or L, E, F) class 2 = L, F, E (or E, F, L) class 3 = F, L, E (or E, L, F)
class 1 = L, F, E (or E, F, L)
class 2 = F, L, E (or E, L, F)
class 3 = F, E, L (or L, E, F)
class 1 = L, F, E (or E, F, L) class 2 = F, L, E (or E, L, F) class 3 = F, E, L (or L, E, F)
class 1 = F, L, E (or E, L, F)
class 2 = F, E, L (or L, E, F)
class 3 = L, F, E (or E, F, L)
class 1 = F, E, L (or L, E, F) class 2 = L, F, E (or E, F, L) class 3 = F, L, E (or E, L, F)
How do simple machines make work easier?(1 point)
Responses
They decrease the distance needed between a person and an object, allowing the person to apply more force and do more work.
They decrease the distance needed between a person and an object, allowing the person to apply more force and do more work.
They reduce the amount of force needed to move an object to do the same amount of work.
They reduce the amount of force needed to move an object to do the same amount of work.
They increase the distance over which a force is needed, doing more work with less force.
They increase the distance over which a force is needed, doing more work with less force.
They magnify the force being applied, thereby decreasing the work they can do with no extra energy exerted by the person using the machine.
They reduce the amount of force needed to move an object to do the same amount of work.
A person using a lever applies 98 Newtons to lift a 20-kilogram box. They apply the force over a distance of 4 meters to lift the box a distance of 2 meters. How much work is done?(1 point)
Responses
196 Joules
196 Joules
80 Joules
80 Joules
392 Joules
392 Joules
40 Joules
196 Joules
A person is lifting a heavy box using a lever. What is the purpose of the lever in this situation?(1 point)
Responses
to reduce the energy needed to lift the box while keeping the direction of the force the same
to reduce the energy needed to lift the box while keeping the direction of the force the same
to reduce the force needed to lift the box and change the direction of the force
to reduce the force needed to lift the box and change the direction of the force
to reduce the energy needed to lift the box and change the direction of the force
to reduce the energy needed to lift the box and change the direction of the force
to reduce the force needed to lift the box while keeping the direction of the force the same