UEE Physics (ЭЕШ Физик) (Mongolia)

A car accelerates from rest along a straight horizontal road with a constant acceleration of 2.5 m/s² for 8.0 s. What is the total distance traveled by the car during this time interval?

• A80 m
• B40 m
• C160 m
• D20 m

A small stone is thrown horizontally with an initial speed of 20 m/s from the top edge of a vertical cliff 45 m high. Taking g = 10 m/s² and neglecting air resistance, what is the horizontal distance from the base of the cliff to the point where the stone strikes the ground?

• A45 m
• B60 m
• C90 m
• D30 m

A wave travels along a rope with a frequency of 50 Hz and a wavelength of 0.40 m. What is the speed of the wave?

• A125 m/s
• B0.008 m/s
• C200 m/s
• D20 m/s

A ball is launched from ground level with an initial velocity of 20 m/s at an angle of 30° above the horizontal. Taking g = 10 m/s² and neglecting air resistance, what is the maximum height reached by the ball?

• A5.0 m
• B10 m
• C15 m
• D20 m

A simple pendulum has a length of 2.5 m. Taking g = 10 m/s² and π ≈ 3.14, what is its period of small oscillations?

• A1.57 s
• B0.50 s
• C12.6 s
• D3.14 s

A 0.40 kg mass is attached to a horizontal spring with spring constant k = 40 N/m. Taking π ≈ 3.14, what is the period of its oscillations?

• A0.10 s
• B62.8 s
• C0.314 s
• D0.628 s

A net horizontal force acts on a 1,200 kg passenger car, increasing its speed from 10 m/s to 25 m/s over a time interval of 5.0 s. What is the magnitude of this net force?

• A1,800 N
• B2,400 N
• C3,600 N
• D6,000 N

A horse pulls a cart forward along a level road. According to Newton's third law of motion, what is the reaction force paired with the forward pull exerted by the horse on the cart?

• AThe friction force exerted by the road surface on the horse's hooves
• BThe backward pull exerted by the cart on the horse
• CThe downward gravitational force of Earth acting on the cart
• DThe backward rolling resistance exerted by the road on the cart's wheels

A 60 kg student stands on a spring scale inside an elevator. If the elevator accelerates upward at 2.0 m/s² and g = 10 m/s², what is the normal force reading shown by the scale?

• A480 N
• B600 N
• C840 N
• D720 N

In an ideal Atwood machine, two blocks with masses m₁ = 3.0 kg and m₂ = 2.0 kg are connected by a light inextensible cord passing over a frictionless, massless pulley. Taking g = 10 m/s², what is the magnitude of the acceleration of the system?

• A2.0 m/s²
• B1.0 m/s²
• C5.0 m/s²
• D10 m/s²

A 10 kg crate rests on a horizontal concrete floor. The coefficient of static friction is μₛ = 0.50, and the coefficient of kinetic friction is μₖ = 0.30. A horizontal pulling force of 25 N is applied to the crate. Taking g = 10 m/s², what is the magnitude of the friction force acting on the crate?

• A25 N
• B30 N
• C50 N
• D0 N

A 4.0 kg wooden block slides down an inclined plane angled at 30° to the horizontal. The coefficient of kinetic friction between the block and the incline is μₖ = 0.20. Taking g = 10 m/s², sin 30° = 0.50, and cos 30° = 0.866, what is the acceleration of the block down the incline?

• A3.27 m/s²
• B5.00 m/s²
• C1.73 m/s²
• D4.13 m/s²

Which property of a sound wave mainly determines the pitch that a listener hears?

• AIts frequency
• BIts amplitude
• CIts speed in the medium
• DIts waveform (overtone content)

According to Newton's law of universal gravitation, if the distance between two spherical masses is doubled while their masses remain unchanged, how does the gravitational attractive force between them change?

• AIt decreases to 1/4 of its original value.
• BIt decreases to 1/2 of its original value.
• CIt increases by a factor of 2.
• DIt increases by a factor of 4.

How is a sound wave traveling through air correctly classified?

• AA transverse electromagnetic wave that can also travel through a vacuum
• BA transverse mechanical wave in which air particles move perpendicular to the wave direct…
• CAn electromagnetic wave that travels at the speed of light
• DA longitudinal mechanical wave consisting of compressions and rarefactions of the air

A satellite of mass m moves in a stable circular orbit at radius r around a planet of mass M. Which expression correctly gives the orbital speed v of the satellite?

• Av = √(GM / r)
• Bv = √(GM / r²)
• Cv = √(2GM / r)
• Dv = GM / r

A hiker shouts toward a vertical cliff and hears the echo 1.5 s later. Taking the speed of sound in air as 340 m/s, how far away is the cliff?

• A510 m
• B127.5 m
• C340 m
• D255 m

A 1,000 kg car rounds a flat unbanked curve of radius 80 m. The coefficient of static friction between the tires and the road surface is μₛ = 0.50. Taking g = 10 m/s², what is the maximum speed at which the car can take the curve without skidding?

• A10 m/s
• B14 m/s
• C20 m/s
• D28 m/s

A small ball of mass m = 0.20 kg is suspended by a light string of length L = 1.0 m and revolves in a horizontal circle as a conical pendulum. The string makes an angle of θ = 60° with the vertical. Taking g = 10 m/s² and cos 60° = 0.50, what is the tension in the string?

• A1.0 N
• B2.0 N
• C3.46 N
• D4.0 N

A small object of mass m attached to a light cord of length R is whirled in a vertical circle. Taking g as the acceleration due to gravity, what is the minimum speed the object must have at the highest point of the trajectory so that the cord does not go slack (tension T ≥ 0)?

• A√(gR)
• B√(2gR)
• C√(3gR)
• D√(5gR)

A mass on a spring with spring constant k = 200 N/m oscillates horizontally without friction with an amplitude of 0.10 m. What is the total mechanical energy of the oscillation?

• A2.0 J
• B10 J
• C20 J
• D1.0 J

A 2.0 kg metal block sliding across a horizontal surface with an initial velocity of 6.0 m/s is brought to rest by friction. By the work-energy theorem, what is the total work done by the friction force on the block?

• A-36 J
• B+36 J
• C-18 J
• D-72 J

A 0.50 kg block attached to a spring with k = 50 N/m oscillates horizontally without friction with an amplitude of 0.20 m. What is the block's maximum speed?

• A0.20 m/s
• B10 m/s
• C4.0 m/s
• D2.0 m/s

A 500 kg roller coaster cart starts from rest at the top of a hill of height h = 20 m and coasts down a frictionless track. Taking g = 10 m/s², what is the speed of the cart at the bottom of the hill?

• A20 m/s
• B14.1 m/s
• C10 m/s
• D40 m/s

A small block slides without friction along a track that loops into a vertical circle of radius R. The block is released from rest at height H above the base of the loop. What is the minimum release height H required so that the block stays on the track at the top of the loop?

• A1.5 R
• B2.0 R
• C2.5 R
• D3.0 R

If the length of a simple pendulum is made 4 times longer (at the same location), how does its period of small oscillations change?

• AIt doubles.
• BIt becomes 4 times longer.
• CIt is halved.
• DIt does not change.

A 1,000 kg passenger car traveling at 15 m/s collides with a stationary 2,000 kg truck on a frictionless icy road, and the two vehicles lock together. What is their combined speed immediately following the collision?

• A3.0 m/s
• B10 m/s
• C7.5 m/s
• D5.0 m/s

A sphere of mass m moving with speed v collides head-on and elastically with a stationary sphere of mass 3m. What is the velocity of the incident sphere of mass m immediately after the collision?

• A-v / 2
• B-v / 3
• C+v / 2
• D0

A uniform horizontal beam of length 4.0 m and mass 20 kg is balanced at its midpoint on a fulcrum. A 30 kg child sits 1.2 m to the left of the fulcrum. At what distance to the right of the fulcrum must a 20 kg child sit to keep the beam in horizontal equilibrium?

• A1.2 m
• B1.5 m
• C1.8 m
• D2.0 m

A string 1.2 m long is fixed at both ends and vibrates in its fundamental (first harmonic) mode. What is the wavelength of this standing wave?

• A1.2 m
• B0.60 m
• C4.8 m
• D2.4 m

A guitar string 0.80 m long is fixed at both ends. Waves travel along it at 240 m/s. What is the frequency of its fundamental (lowest) mode?

• A300 Hz
• B75 Hz
• C192 Hz
• D150 Hz

A diver descends to a depth of 20 m in fresh water (density ρ = 1,000 kg/m³). Taking g = 10 m/s² and atmospheric pressure p₀ = 1.0 × 10⁵ Pa, what is the total absolute pressure experienced by the diver at this depth?

• A2.0 × 10⁵ Pa
• B2.5 × 10⁵ Pa
• C4.0 × 10⁵ Pa
• D3.0 × 10⁵ Pa

In a hydraulic press, the input piston has a cross-sectional area of A₁ = 20 cm² and the output piston has an area of A₂ = 400 cm². What input force must be applied to the small piston to support a load of mass 1,600 kg on the large piston? (g = 10 m/s²)

• A400 N
• B800 N
• C1,600 N
• D3,200 N

A wooden block with density ρ_wood = 600 kg/m³ floats in static equilibrium in water (density ρ_water = 1,000 kg/m³). What percentage of the block's total volume is submerged beneath the water surface?

• A40%
• B50%
• C60%
• D80%

A solid metal sphere of mass 7.8 kg and volume 0.0010 m³ is suspended by a light cord and completely submerged in water (density ρ = 1,000 kg/m³). Taking g = 10 m/s², what is the tension in the cord?

• A58 N
• B68 N
• C78 N
• D88 N

An ideal gas held at constant temperature undergoes an isothermal compression that reduces its volume to one-third of its initial value (V₂ = V₁ / 3). If the initial pressure was p₁ = 120 kPa, what is the final pressure p₂?

• A40 kPa
• B120 kPa
• C240 kPa
• D360 kPa

A rigid sealed container holds an ideal gas at an initial temperature of 27 °C (300 K) under a pressure of 1.5 × 10⁵ Pa. If the gas is heated to 127 °C (400 K) at constant volume, what is the final pressure?

• A1.8 × 10⁵ Pa
• B2.0 × 10⁵ Pa
• C2.5 × 10⁵ Pa
• D7.0 × 10⁵ Pa

A 4.0 mole sample of an ideal gas is confined to a container of volume 0.0831 m³ at a temperature of 300 K. Taking the universal gas constant R = 8.31 J/(mol·K), what is the pressure of the gas?

• A6.0 × 10⁴ Pa
• B1.2 × 10⁵ Pa
• C2.4 × 10⁵ Pa
• D3.6 × 10⁵ Pa

According to the kinetic theory of gases, the root-mean-square (rms) speed of molecules in an ideal gas depends on the absolute temperature T according to which proportionality?

• ADirectly proportional to the square root of absolute temperature (v_rms ∝ √T)
• BDirectly proportional to the absolute temperature (v_rms ∝ T)
• CDirectly proportional to the square of absolute temperature (v_rms ∝ T²)
• DIndependent of temperature, depending only on gas pressure

An ideal gas expands isobarically at a constant pressure of 2.5 × 10⁵ Pa from an initial volume of 0.020 m³ to a final volume of 0.060 m³. How much mechanical work is performed by the expanding gas?

• A5.0 kJ
• B25 kJ
• C15 kJ
• D10 kJ

During an isochoric (constant volume) heating process, 800 J of thermal energy is transferred into an ideal gas. How much mechanical work is done by the gas during this process?

• A0 J
• B400 J
• C800 J
• D1,200 J

In a thermodynamic process, a gas absorbs 1,500 J of heat from its surroundings while performing 600 J of work on an external piston. What is the change in the internal energy of the gas?

• A-900 J
• B+600 J
• C+900 J
• D+2,100 J

When a closed cyclic thermodynamic process is plotted on a pressure-volume (p-V) diagram, what does the area enclosed within the cycle loop represent?

• AThe total change in internal energy over one complete cycle
• BThe net mechanical work done by the gas during one complete cycle
• CThe total heat absorbed by the working substance during the expansion phase alone
• DThe ratio of hot reservoir temperature to cold reservoir temperature

What is the total internal energy U of 3.0 moles of an ideal monatomic gas at a temperature of 300 K? (Take universal gas constant R = 8.31 J/(mol·K))

• A3.74 kJ
• B7.48 kJ
• C11.2 kJ
• D18.7 kJ

In an ideal adiabatic process involving a gas, which condition is strictly satisfied by definition?

• ANo heat is exchanged between the gas and its surroundings (Q = 0).
• BThe temperature of the gas remains strictly constant (ΔT = 0).
• CNo mechanical work is performed by or on the gas (W = 0).
• DThe pressure of the gas remains strictly constant (Δp = 0).

During a rapid adiabatic expansion, an ideal gas performs 450 J of mechanical work on its surroundings. What is the change in the internal energy (ΔU) of the gas?

• A+450 J
• B-450 J
• C0 J
• D-900 J

For an ideal monatomic gas, the molar heat capacities at constant pressure and constant volume are C_p = (5/2)R and C_v = (3/2)R, respectively. What is the adiabatic index (heat capacity ratio) γ = C_p / C_v for this gas?

• A1.25
• B1.40
• C1.67
• D2.50

How much thermal energy is required to raise the temperature of 2.0 kg of liquid water from 20 °C to 80 °C? (Specific heat capacity of water c = 4,200 J/(kg·°C))

• A168 kJ
• B252 kJ
• C504 kJ
• D672 kJ