Exam 1: A: Foundations

The two water reservoirs shown in the figure are open to the atmosphere,and the water has density 1000 kg/m³.The manometer contains incompressible mercury with a density of 13,600 kg/m³.What is the difference in elevation h if the manometer reading m is 25.0 cm?

A 0.500-kg ball traveling horizontally on a frictionless surface approaches a very massive stone at 20.0 m/s perpendicular to wall and rebounds with 70.0% of its initial kinetic energy. What is the magnitude of the change in momentum of the stone?

A very small object carrying -6.0 μC of charge is attracted to a large,well-anchored,positively charged object.How much kinetic energy does the negatively charged object gain if the potential difference through which it moves is 3.0 mV? (k = 1/4πε₀ = 8.99 × 10⁹ N • m²/C²)

When a 2.75-kg fan,having blades 18.5 cm long,is turned off,its angular speed decreases uniformly from 10.0 rad/s to 6.30 rad/s in 5.00 s. (a)What is the magnitude of the angular acceleration of the fan? (b)Through what angle (in degrees)does it turn while it is slowing down during the 5.00 s? (c)If its angular acceleration does not change,how long after it is turned off does it take the fan to stop.

Two blocks are connected by a string that goes over an ideal pulley as shown in the figure.Block A has a mass of 3.00 kg and can slide over a rough plane inclined 30.0° to the horizontal.The coefficient of kinetic friction between block A and the plane is 0.400.Block B has a mass of 2.77 kg.What is the acceleration of the blocks?

The magnitude of the Poynting vector of a planar electromagnetic wave has an average value of 0.939 W/m².The wave is incident upon a rectangular area,1.5 m by 2.0 m,at right angles.How much total electromagnetic energy falls on the area during 1.0 minute? (c = 3.0 × 10⁸ m/s,μ₀ = 4π × 10^-7 T • m/A, Ε₀ = 8.85 × 10^-12 C²/N • m²)

In the lab,a relativistic proton has a momentum of 1.00 × 10^-19 kg ∙ m/s and a rest energy of 0.150 nJ.What is the speed of the proton in the lab? (c = 3.00 × 10⁸ m/s,m_proton = 1.67 × 10^-27 kg)

An ideal massless spring with a spring constant of 2.00 N/m is attached to an object of 75.0 g.The system has a small amount of damping.If the amplitude of the oscillations decreases from 10.0 mm to 5.00 mm in 15.0 s,what is the magnitude of the damping constant b?

An 84-kW AM radio station broadcasts at 1000 kHz .How many photons are emitted each second by the transmitting antenna? (h = 6.626 × 10^-34 J • s)

A certain crying baby emits sound with an intensity of 8.0 × 10^-8 W/m².What is the intensity level due to a set of five such crying babies,all crying with the same intensity? You can neglect any absorption,reflection,or interference of the sound.The lowest detectable intensity is 1.0 × 10^-12 W/m².

A rabbit trying to escape a fox runs north for 8.0 m,darts northwest for 1.0 m,then drops 1.0 m down a hole into its burrow.What is the magnitude of the net displacement of the rabbit?

The value of the dot product of two vectors depends on the particular coordinate system being used.

A 480-kg car moving at 14.4 m/s hits from behind a 570-kg car moving at 13.3 m/s in the same direction.If the new speed of the heavier car is 14.0 m/s,what is the speed of the lighter car after the collision,assuming that any unbalanced forces on the system are negligibly small?

A box of mass m is pressed against (but is not attached to)an ideal spring of force constant k and negligible mass,compressing the spring a distance x.After it is released,the box slides up a frictionless incline as shown in the figure and eventually stops.If we repeat this experiment but instead compress the spring a distance of 2x

A radio telescope 200 m in diameter is used to investigate sources emitting a 21-cm wavelength wave.What is the minimum angular separation of the sources that can be resolved by this system?

A 4.0-cm tall object is placed 50.0 cm from a diverging lens having a focal length of magnitude 25.0 cm.What are the nature and location of the image? The image is

As you stand by the side of the road,a car approaches you at a constant speed,sounding its horn,and you hear a frequency of 80.0 Hz.After the car goes by,you hear a frequency of 60.0 Hz.What is the speed of the car? The speed of sound in the air is 343 m/s.

In a section of horizontal pipe with a diameter of 3.00 cm the pressure is 5.21 kPa and water is flowing with a speed of 1.50 m/s.The pipe narrows to 2.50 cm.What is the pressure in the narrower region if water behaves like an ideal fluid of density 1000 kg/m³?

It requires 49 J of work to stretch an ideal very light spring from a length of 1.4 m to a length of 2.9 m.What is the value of the spring constant of this spring?

A 50.0-kg box rests on a horizontal surface.The coefficient of static friction between the box and the surface is 0.300 and the coefficient of kinetic friction is 0.200.What is the friction force on the box if (a) a horizontal 140-N push is applied to it? (b) a horizontal 175-N push is applied to it?