26. A 4.00 kg mass is in uniform circular motion as shown in the figure. The string to which the mass is attached has a length of L = 3.00 m and forms an angle of θ = 50.0° with the vertical. What is the speed of the mass?

 

 

 

 

 

 

27. A 2.0 kg mass moves at 10.0 m/s when it has a collision in space. The mass’s speed was unchanged, but the direction of its velocity was altered by 80°. If the collision lasted 0.25 s, what was the magnitude of the average force exerted on the mass?

28. A shipment of parts is labeled in units of “ohm∙second.” Which one of the following choices represents an equivalent unit?

 

 

 

 

 

31. A solid cylinder rolls without slipping on a rough inclined plane. Which one of the following choices best represents the type and direction of friction (if any) acting on the cylinder as it rolls up the incline?

 

 

33. Two long wires are fixed in space so that the conventional current in the left wire (2 A) comes out of the plane of the page and the conventional current in the right wire (3 A) goes into the plane of the page. In which Region(s) is there a place on the x-axis (aside from infinity) at which the magnetic field is equal to zero from these currents?

 

 

34. A 9.20 m long uniform plank rests on a frictionless ice pond. A 52 kg box rests on the plank’s left end while a 71 kg person stands at the plank’s right end. After the person walks to the left on the plank and stands at the same location as the box, the plank has slid 3.84 m to the right relative to the pond’s shore. Which one of the following choices best represents the mass of the plank?

 

 

 

 

 

 

 

38. A small 2.0 kg block rests at the bottom of a bucket. The bucket is spun in a vertical circle of radius L by a rope. When the bucket reaches the highest point in its motion, it moves just fast enough for the block to remain in place in the bucket. When the bucket is at an angle θ = 30° from the vertical, as seen in the figure, what is the magnitude of the normal force (perpendicular to the surface) provided by the bucket onto the block? Note that the direction of the gravitational field is indicated in the diagram by and that the block does not touch any sides of the bucket aside from the bottom of it.

39. A point wave source travels along the x-axis at constant speed v_S. Stationary observers on the x-axis measure the wavelength of the waves that they receive. The ratio of the wavelength measured at a location behind the source to the wavelength measured at a location in front of the source is 1.50. If the wave speed is v, what is the source speed v_S?

 

 

 

 

40. A small object of mass M is released from rest at the top of a frictionless incline. The incline has a mass M and makes an angle θ with the horizontal. The incline remains at rest on a table as the small object slides. During the slide, what is the magnitude of the normal force from the table on the incline?

 

 

 

 

 

 

 

 

 

 

 

 

 

42. A long uniform rod, pivoted at one end affixed to the ground, is in static equilibrium A horizontal rope acts 75% of the way up the rod while a vertical rope acts at the far end. The magnitude of each rope’s force is the same as the gravitational force acting on the rod. What is the value of the angle θ in the figure?

 

 

 

43. A semi-circle has radius R, total charge Q, and a charge per unit length given asλ = λ_o cos θ with θ defined in the figure and 𝜆_oa positive constant. Which one of the following choices gives the electric field strength at the point labeled P?

 

48. In the binary star system shown, the two stars follow circular orbits about the system’s center of mass. The stars are separated by a distance D that is large compared to their size and are subject only to their mutual gravitational attraction. The orbital period of the star of mass M is T. Which one of the following choices represents the total mass of the binary star system?

49. Two identical particles travel to the right. The particle traveling at 2.40 × 10⁸ m/s collides with and sticks to the other particle traveling at 1.80×10⁸ m/s. Which one of the following choices best represents the speed of the resulting object after collision?