SNEAD STATE PHYSICS 1 FINAL EXAM | QUESTIONS AND ANSWERS | 2027 UPDATE | SOLVED 100% CORRECT.

SNEAD STATE PHYSICS 1 FINAL EXAM | QUESTIONS AND ANSWERS | 2027 UPDATE | SOLVED 100% CORRECT. A 1500 kg car is traveling along a straight road at 20 m/s. Two seconds later its speed is 21 m/s. What is the magnitude of the net force acting on the car during this time? - ANSWER -acceleration= 0.5 m/s^2 force= 750 N Are the objects described here in static equilibrium, dynamic equilibrium, or not in equilibrium at all? a) a girder is lifted at constant speed by a crane b) a grinder is lowered by a crane. It is slowing down. c) you're straining to hold a 200 lb barbell over your head d) a jet plane has reached its cruising speed and altitude e) a rock is falling into the grand canyon f) a box in the back of a truck does not slide as the truck stops - ANSWER -a) a girder is lifted at constant speed by a crane (Dynamic equilibrium) b) a grinder is lowered by a crane. It is slowing down.( dynamic equilibrium) c) you're straining to hold a 200 lb barbell over your head (static equilibrium) d) a jet plane has reached its cruising speed and altitude (dynamic equilibrium) e) a rock is falling into the grand canyon ( is not in equilibrium state) f) a box in the back of a truck does not slide as the truck stops (dynamic equilibrium) Suppose you are holding a box in front of you and away from your body by squeezing the sides. Draw a free-body diagram showing all of the forces on the box. What is the force that is holding the box up, the force that is opposite the weight force? - ANSWER -Force is responsible for still motion is static frictional force The three ropes in the figure are tied to a small, very light ring. Two of the ropes are anchored to the walls at right angles, and the third rope pulls as shown. What are T1 and T2, the magnitudes of the tension forces in the first two ropes? - ANSWER -The first ropes tension is 86.6N and the second rope is 50 N What is the tension in the rope of Figure P5.42? - ANSWER -588 N the horse on a carousel is 4.0 m from the central axis. a) if the carousel rotates at 0.10 rev/s, how long does it take the horse to go around twice? b) how fast is a child on the horse going (in m/s)? - ANSWER -a) 20 s b) 2.5 m/s A 5.0 m diameter merry-go-round is turning with a 4.0 s period. What is the speed of a child on the rim? - ANSWER -3.93 m/s A 200 g block on a 50cm long string swings in a circle on a horizontal, frictionless table at 75 rpm. a) what is the speed of the block? b) what is the tension in the string? - ANSWER -a) 7.85 rad/s b) 3.93 m/s You hold a bucket in one hand. In the bucket is a 500 g rock. You swing the bucket so the rock moves in a vertical circle 2.2 m in diameter. What is the minimum speed the rock must have at the top of the circle if it is to stay in contact with the bottom of the bucket? - ANSWER -3.28 m/s What is the angular speed of the tip of the minute hand on a clock in rad/s? - ANSWER -1.74 x 10^-3 rad/s Figure P7.9 shows the angular position of a potter's wheel. a) what is the angular displacement of the wheel between t= 5s and t= 15 s? b) what is the angular velocity of the wheel at t=15s? - ANSWER -a) 25 rad b) 10 rad s^-1 The crankshaft in a race goes from the rest to 3000 rpm in 2.0s. a) what is the crankshaft's angular acceleration? b) how many revolutions does it make while reaching 3000 rpm? - ANSWER -a) 157 rad/s^2 b)50 revolutions A 64 kg students stands on a very light, rigid board that rests on a bathroom scale at each end, as shown in figured P8.1 What is the reading on each of the scales? - ANSWER -156.96 N One end of a spring is attached to a wall. A 25 N pull on the other end causes the spring to stretch by 3.0 . What is the spring constant? - ANSWER -833.3 N/m How much force does it take to stretch a 10 m long, 1.0 cm diameter steel cable by 5.0 mm? - ANSWER -79 x 10^2 N At what speed do a bicycle and its rider, with a combined mass of 100 kg, have the same momentum as a 1500 kg car traveling at 1.0 m/s? - ANSWER -15 m/s A small, 100 g cart is moving at 1.20 m/s on a frictionless track when it collides with a larger, 1.00 kg cart at rest. After the collision, the small cart recoils at 0.850 m/s. What is the speed of the large cart after the collision? - ANSWER -0.205 m/s A little girl is going on the merry-go-round for the first time, and wants her 47 kg mother to stand next to her on the ride, 2.6 m from the merry-go-round's center. If her mother's speed is 4.2 m/s when the ride is in motion, what is her angular momentum around the center of the merry-go-round? - ANSWER -213.87 kg x m^2 /s A 2.0 kg book is lying on a 0.75 m high table, you pick it up and place it on a bookshelf 2.3 m above the floor. During this process, a) how much work foes gravity do on the book? b) how much work foes your hand do on the book? - ANSWER -a) -30.38 J b) 30.38 J Which has the larger kinetic energy, a 10 g bullet fired at 500 m/s or a 10 kg bowling ball sliding at 10 m/s? - ANSWER -the bullet has a larger kinetic energy