Exam 1: A: Foundations

A futuristic design for a car is to have a large solid disk-shaped flywheel within the car storing kinetic energy.The uniform flywheel has mass 370 kg with a radius of 0.500 m and can rotate up to 230 rev/s.Assuming all of this stored kinetic energy could be transferred to the linear velocity of the 1600-kg car,find the maximum attainable speed of the car.

An LRC ac series circuit has R = 15 Ω,L = 25 mH,and C = 30 μF.The circuit is connected to a 120-V (rms)ac source with frequency 200 Hz. (a)What is the average power dissipated by the circuit? (b)What is the power factor for the circuit?

If the fastest you can safely drive is 65 mi/h,what is the longest time you can stop for dinner if you must travel 541 mi in 9.6 h total?

When a 100-Ω resistor is connected across the terminals of a battery of emf ε and internal resistance r,the battery delivers 0.794 W of power to the 100-Ω resistor. When the 100-Ω resistor is replaced by a 200-Ω resistor,the battery delivers 0.401 W of power to the 200-Ω resistor.What are the emf and internal resistance of the battery?

An object 4.0 cm in height is placed 8.0 cm in front of a concave spherical mirror with a focal length of 10.0 cm.What is the position of its image in relation to the mirror,and what are the characteristics of the image?

If an object is accelerating toward a point,then it must be getting closer and closer to that point.

Thirteen resistors are connected across points A and B as shown in the figure.If all the resistors are accurate to 2 significant figures,what is the equivalent resistance between points A and B?

Two identical small conducting spheres are separated by 0.60 m.The spheres carry different amounts of charge and each sphere experiences an attractive electric force of 10.8N.The total charge on the two spheres is -24 μC.The two spheres are now connected by a slender conducting wire,which is then removed.The electric force on each sphere is closest to

A 60.0-kg person rides in elevator while standing on a scale. The elevator is traveling downward but slowing down at a rate of 2.00 m/s². The reading on the scale is closest to

A 5.0-kg block is attached to an ideal massless spring whose spring constant is 125 N/m.The block is pulled from its equilibrium position at x = 0.00 m to a position at x = +0.687 m and is released from rest.The block then executes lightly damped oscillation along the x-axis,and the damping force is proportional to the velocity.When the block first returns to x = 0.00 m,its x component of velocity is -2.0 m/s and its x component of acceleration is +5.6 m/s². (a)What is the magnitude of the acceleration of the block upon release at x = +0.687 m. (b)Find the damping constant b.

An incompressible fluid flows steadily through a pipe that has a change in diameter.The fluid speed at a location where the pipe diameter is 8.0 cm is 1.28 m/s.What is the fluid speed at a location where the diameter has narrowed to 4.0 cm?

A hockey puck slides off the edge of a table at point A with an initial velocity of 20.0 m/s and experiences no air resistance.The height of the tabletop above the ground is 2.00 m. (a)What is the speed (not the velocity)of the puck just before it touches the ground? (b)What is the distance between point A and the point where the puck hits the ground?

A solenoid is wound with 970 turns on a form 4.0 cm in diameter and 50 cm long.The windings carry a current I in the sense that is shown in the figure.The current produces a magnetic field,of magnitude 4.3 mT,near the center of the solenoid.Find the current in the solenoid windings.(μ₀ = 4π × 10^-7 T • m/A)

A single-slit diffraction pattern is formed on a distant screen.Assuming the angles involved are small,by what factor will the width of the central bright spot on the screen change if the slit width is doubled?

Which one of the following free-body diagrams best represents the free-body diagram,with correct relative force magnitudes,of a person in an elevator that is traveling upward but is gradually slowing down at a rate of 9 m/s²? _f is the force of the floor on the person and _g is the force of gravity on the person.

A board that is 20.0 cm wide,5.00 cm thick,and 3.00 m long has a density 350 kg/m³. The board is floating partially submerged in water of density 1000 kg/m³. What fraction of the volume of the board is above the surface of the water?

A person pushes horizontally on a heavy box and slides it across the level floor at constant velocity.The person pushes with a 60.0 N force for the first 6.88 m,at which time he begins to tire.The force he exerts then starts to decrease linearly from 60.0 N to 0.00 N across the remaining 6.88 m.How much total work did the person do on the box?

The exhaust fan on a typical kitchen stove pulls 600 CFM (cubic feet per minute)through the filter.Given that 1.00 in.= 2.54 cm,how many cubic meters per second does this fan pull?

A projectile is fired from point 0 at the edge of a cliff,with initial velocity components of v_0x= 60 m/s and v_0y = 175 m/s,as shown in the figure.The projectile rises and then falls into the sea at point P.The time of flight of the projectile is 40.0 s,and it experiences no appreciable air resistance in flight.What is the magnitude of the velocity of the projectile 21.0 s after it is fired?

A ball is released from rest on a no-slip surface,as shown in the figure.After reaching its lowest point,the ball begins to rise again,this time on a frictionless surface as shown in the figure.When the ball reaches its maximum height on the frictionless surface,it is