A spiral staircase in a building is in the shape of a helix of radius 5 meters. Between two oors of the building, the stairs make one full revolution and climb by 4 meters. A person carries a bag of groceries up two oors. The combined mass of the person and the groceries is 70 kg and the gravitational force is 70g downward, where g is the acceleration due to gravity. Use a line integral to calculate the work done by gravity against the person.

Which terms describe the purpose of antennas on devices that use radio waves? transmit and receivemodify and amplifyamplify and receivemodify and transmit

Waves that cause the most damage during an earthquake are a. surface waves c. s waves b. p waves d. ocean waves

Aperson stands on a platform, initially at rest, that can rotate freely without friction. the moment of inertia of the person plus the platform is ip. the person holds a spinning bicycle wheel with its axis horizontal. the wheel has moment of inertia iw and angular velocity ωw. take the ωw direction counterclockwise when viewed from above. part a what will be the angular velocity ωp of the platform if the person moves the axis of the wheel so that it points vertically upward?