PHY107 Practice Exam 2-Below you will find practice questions for your 107 exam. Please keep inmind that these are only samples, and the number of questions, numberof questions per topic and point values per question will likely bedifferent.1.. A wheel starts from rest and has an angular acceleration that is given by (t) = (6.0rad/s2)t2 where t is in seconds. After it has rotated through 10 revolutions, its angular velocity is: A) 63 rad/sB) 75 rad/s C) 89 rad/sD) 130 rad/s E) 210 rad/s2. The block shown moves with constant velocity on a horizontal surface. Two of the forces on itare shown. A frictional force exerted by the surface is the only other horizontal force on the block. The frictional force is:A) 0 NB) 2 N, leftwardC) 2 N, rightwardD) slightly more than 2 N, leftwardE) slightly less than 2 N, leftward3 A block moves at 5 m/s in the positive x direction and hits an identical block, initially at rest. A small amount of gunpowder had been placed on one of the blocks. The explosion does not harm the blocks but it doubles their total kinetic energy. After the explosion the blocks move along the x axis and the incident block has a speed of: A) 1.8 m/sB) 3.2 m/s C) 5.0 m/sD) 6.8 m/sE) 7.1 m/s14. Blocks A and B are moving toward each other. A has a mass of 2.0 kg and a velocity of 50 m/s, while B has a mass of 4.0 kg and a velocity of –25 m/s. They suffer a completely inelastic collision. The kinetic energy lost during the collision is: A) 0 JB) 1250 J C) 3750 J D) 5000 J E) 5600 J 5. A 2.0-kg mass is attached to one end of a spring with a spring constant of 100 N/m and a 4.0-kg mass is attached to the other end. The masses are placed on a horizontal surface and the springis compressed 10 cm. The spring is then released with the masses at rest and the masses oscillate.When the spring has its equilibrium length for the first time the 2.0-kg mass has a speed of 0.36 m/s. The mechanical energy that has been lost to this instant is: A) 0 JB) 0.31 JC) 0.61 JD) 0.81 JE) 1.2 J6. The fan shown has been turned on and is slowing as it rotates clockwise. The direction of the acceleration of the point X on the fan tip could be:A) B) C) D) E) 27. A flywheel is initially rotating at 20 rad/s and has a constant angular acceleration. After 9.0 s it has rotated through 450 rad. Its angular acceleration is: A) 3.3 rad/sB) 4.4 rad/sC) 6.7 rad/sD) 11 rad/sE) 48 rad/s8. A pulley with a radius of 3.0 cm and a rotational inertia of 4.5  10–3 kg∙m2 is suspended from the ceiling. A rope passes over it with a 2.0-kg block attached to one end and a 4.0-kg block attached to the other. The rope does not slip on the pulley. When the velocity of the heavier blockis 2.0 m/s the total kinetic energy of the pulley and blocks is: A) 2.0 J B) 12 J C) 14 J D) 22 J E) 28 J 9. A 40-N crate rests on a rough horizontal floor. A 12-N horizontal force is then applied to it. Ifthe coefficients of friction are s = 0.5 and k = 0.4, the magnitude of the frictional force on the crate is: A) 8 N B) 12 N C) 16 N D) 20 N E) 40 N10. A block of mass m is pulled along a rough horizontal floor by an applied force T as shown. The vertical component of the force exerted on the block by the floor is: A) mg B) mg – T cos C) mg + T cos D) mg – T sin E) mg + T sin 311. A force F (larger than the largest possible force of static friction) is applied to the left to an object moving to the right on a horizontal surface. Then: A) the object must be moving at constant speed B) F and the friction force act in opposite directions C) the object must be slowing down D) the object must be speeding up E) the object will come to rest and remain at rest 12. A thin rod of length L has a density that increases along its length, ρ = ρ0x. What is the rotational inertia of the rod around its less dense end?A) ML2/12 B) ML2/6 C) ML2/3 D) ML2/2 E) ML213. An object of mass m and another object of mass 2m are each forced to move along a circle ofradius 1.0 m at a constant speed of 1.0 m/s. The magnitudes of their accelerations are: A) equal B) in the ratio of √2 : 1 C) in the ratio of 2 : 1 D) in the ratio of 4 : 1 E) zero 14. If a certain car, going with speed v1, rounds a level curve with a radius R1, it is just on the verge of skidding. If its speed is now doubled, the radius of the tightest curve on the same road that it can round without skidding is: A) 2R1B) 4R1C) R1/2 D) R1/4 E) R115. A thin circular hoop of mass 1.0 kg and radius 2.0 m is rotating about an axis through its center and perpendicular to its plane. It is slowing down at the rate of 7.0 rad/s2. The net torque acting on it is: A) 7.0 N∙m B) 14 N∙m C) 28 N∙m D) 44 N∙m E) none of these 16. Two trailers, X with mass 500 kg and Y with mass 2000 kg, are being pulled at the same speed. The ratio of the kinetic energy of Y to that of X is: A) 1:1 B) 2:1 C) 4:1 D) 9:1 E) 1500:1 17. A boy holds a 40-N weight at arm's length for 10 s. His arm is 1.5 m above the ground. The work done by the force of the boy on the weight while he is holding it is: A) 0 J B) 6.1 J C) 40 J D) 60 J E) 90 J418. A sledge (including load) weighs 5000 N. It is pulled on level snow by a dog team exerting ahorizontal force on it. The coefficient of kinetic friction between sledge and snow is 0.05. How much work is done by the dog team pulling the sledge 1000 m at constant speed? A) 0 J B) 2.5  105 J C) 5.0  105 J D) 2.5  106 J E) 5.0  106 J19. An object moves in a circle at constant speed. The work done by the centripetal force is zero because: A) the displacement for each revolution is zero B) the average force for each revolution is zero C) there is no friction D) the magnitude of the acceleration is zero E) the centripetal force is perpendicular to the velocity 20. In raising an object to a given height by means of an inclined plane, as compared with raising the object vertically, there is a reduction in: A) work required B) distance …