Which example represents a class 2 lever? (1 point)
• a car door being opened and shut
• a screwdriver opening a paint can
• tweezers plucking hairs
• salad tongs picking up salad
• a screwdriver opening a paint can
Which statement best describes energy? (1 point)
• Energy is the power derived from the utilization of simple machines.
• Energy is the force that causes movement in an object.
• Energy is the ability to do work.
• Energy is a push or pull on an object that will change the motion of the object.
• Energy is the ability to do work.
Which statement best describes work? (1 point)
• Work is done when a force causes an object to move.
• Work is done whenever a force acts on an object.
• Work is done whenever an object is held in place by multiple forces.
• Work is done when an object continues in motion without a push.
• Work is done when a force causes an object to move.
A shovel performs several different functions. One of these is that it gives mechanical advantage as a lever. When does it act like a lever? (1 point)
• when the shovel is in the dirt and you push down against the end of the shovel, making it pivot when you step up onto the shovel • • with both feet to use your body weight
• when the soil is lifted with the dirt at the end of the shovel and a lifting force at the handle
• when you push the shovel downward into the dirt and a small force allows you to push down into the dirt easily
• when the shovel is in the dirt and you push down against the end of the shovel, making it pivot when you step up onto the shovel with both feet to use your body weight
A shovel performs several different functions. One of these is that it gives mechanical advantage as a lever. When does it act like a lever? (1 point)
• when the shovel is in the dirt and you push down against the end of the shovel, making it pivot
• when you step up onto the shovel with both feet to use your body weight
• when the soil is lifted with the dirt at the end of the shovel and a lifting force at the handle
• when you push the shovel downward into the dirt and a small force allows you to push down into the dirt easily
• when the shovel is in the dirt and you push down against the end of the shovel, making it pivot
A person uses a screwdriver as a lever to open a can of paint. Where is the fulcrum in this situation? (1 point)
• the point where the end of the screwdriver lifts up the lid of the can
• the point where the screwdriver touches the rim of the can
• the point where the person pushes down on the screwdriver
• the point where the person holds onto the can to keep it in place