45. The nurse is assessing a young child in the emergency department who drools and is agitated. The nurse can hear a stridor on inhalation across the room. Which condition should the nurse suspect in the patient?

Note the following situations: In which case will the magnitude of the normal force on the block be equal to (Mg + F sin )?  

Which one of the following statements concerning kinetic energy is true?

A 77.0 kg astronaut pushes to the left on a spacecraft with a force  in “gravity-free” space.  The spacecraft has a total mass of 1.0 × 104 kg.  During the push, the astronaut accelerates to the right with an acceleration of 0.8 m/s2. Determine the magnitude of the acceleration of the spacecraft.

(4 points) Two smooth disks about the size of drink coasters are identical in size and overall appearance, except that one is composed of radioactive cobalt (Co) and the other of iron (Fe), which is not radioactive. The two disks are exactly the same size; their weights are slightly different because they are made from different materials. However, no scale is available to measure the weight and you are unable to discern which one is heavier by handling them (something you must avoid since one is radioactive).However, there is an air hockey table available (i.e., an air table on which the disks can move with nearly zero friction). You have been given the task to determine which of the two disks is radioactive (a radiation detector is not available).Describe a one-dimensional collision experiment that does not require measuring the masses or speeds of the disks that uses the air hockey table to reveal which disk is heavier, and explain how it will provide the information that you seek.The densities of the materials in g/cm3 are: Fe (7.86) and Co (8.90).

During a certain process, the linear momentum of a system is conserved. Which one of the following statements concerning this system is correct?

Complete the following statement: In an isolated system, the total mechanical energy remains constant if

An arrow is launched straight up from the surface of the Earth.  Which one of the following statements describes the energy transformation of the arrow as it rises?  Neglect air resistance.

A 50.0 kg boy runs at a speed of 10.0 m/s and jumps onto a cart as shown in the figure.  The cart is initially at rest.  If the speed of the cart with the boy on it is 2.50 m/s, what is the mass of the cart?

Which one of the following provides a basis to distinguish among different types of collisions?