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A physical quantity consists of a magnitude and a unit.
Which row does not show a correct combination of a quantity and its unit? [Table_1]
A small car travels in a town.
What is a reasonable estimate of the kinetic energy of the car?
A solid bar has a square cross-section. Its length is measured as 50.0 ± 0.2 cm and its width is measured as 2.00 ± 0.01 cm.
These values are used to calculate the volume of the bar.
What is the percentage uncertainty in the calculated volume?
The graph shows how the acceleration of an object moving in a straight line varies with time.
The object starts from rest.
Which graph shows the variation with time of the velocity of the object over the same time interval?
A stone falls vertically from rest. Air resistance is negligible.
What is the speed of the stone when it has fallen through a distance of 0.40 m?
A ball is thrown horizontally off a tall building. The ground is horizontal. Air resistance is negligible.
Which statement about the motion of the ball is correct?
A moving object strikes a stationary object. The collision is inelastic. The objects move off together.
Assume that the two objects form an isolated system.
Which row shows the possible values of total momentum and total kinetic energy for the system before and after the collision?
The graph shows how a quantity Y varies with a quantity X for an object falling vertically at its terminal velocity towards the surface of the Earth.
Which quantities could X and Y represent?
A ball of mass 2.0 kg travels horizontally with a speed of 4.0 m s$^{-1}$. The ball collides with a wall and rebounds in the opposite direction with a speed of 2.8 m s$^{-1}$. The time of the collision is 150 ms.
What is the average force exerted on the wall?
Two train carriages each of mass 5000 kg roll toward one another on a horizontal frictionless track. One is travelling at a speed of 2.00 $m s^{-1}$ and the other at a speed of 1.00 $m s^{-1}$, as shown.
They collide and join together.
What is the kinetic energy lost during the collision?
Which single condition must apply for an object to be in equilibrium?
A kite is in equilibrium at the end of a string, as shown.
The kite has three forces acting on it: the weight $W$, the tension $T$ in the string, and the force $F$ from the wind.
Which vector diagram represents the forces acting on the kite?
Four forces act about a point P, as shown.
The forces act in the same plane and produce no resultant moment about point P.
What is the length XY?
A rectangular block of lead of density $1.13 \times 10^4 \text{ kg m}^{-3}$ has sides of length 12.0 cm, 15.0 cm and 10.0 cm.
What is the maximum pressure the block can exert when resting on a table?
What is the definition of power?
A model car travels at a constant velocity of 12 m s$^{-1}$ in a straight horizontal line. The input power to the engine of the car is 800 W. The efficiency of the engine is 60%.
What is the total horizontal resistive force on the car?
Which statement represents the principle of conservation of energy?
A barrel of mass 50 kg is loaded onto the back of a lorry 1.6 m high by pushing it up a frictionless plank 3.4 m long.
What is the minimum work done?
What is a unit for stress?
The graph shows the relationship between stress and strain for three wires of the same linear dimensions but made from different materials.
Which statements are correct?
- The extension of P is approximately twice that of Q for the same stress.
- The ratio of the Young modulus for P to that of Q is approximately two.
- For strain less than 0.1, R obeys Hooke’s law.
Four solid steel rods equally support an object weighing 10 kN. Each rod is of length 2.0 m and cross-sectional area 250 mm2. The weight of the object causes the rods to contract by 0.10 mm. The rods obey Hooke’s law.
What is the Young modulus of steel?
The graph shows how the length of a spring varies with the force applied to it. Two areas P and Q are labelled.
Which area represents the work done in stretching the spring?
A horizontal beam of vertically polarised light of amplitude $A$ is incident normally on a polarising filter. The transmission axis of the filter is at an angle of $50^\circ$ to the vertical.
What is the amplitude of the light in the beam after it has passed through the filter?
A progressive longitudinal sound wave moves through air. The diagram shows the positions of the air particles along part of the wave at one instant.
Point Q is a distance x from point P.
Which graph shows the variation of the displacement of the air particles with distance from P along the wave?
An electromagnetic wave in free space has a frequency of $3.0 \times 10^{16}$ Hz.
Which row gives the principal region of this wave and an example of an electromagnetic wave with a lower frequency?
A source of sound emits waves of a constant frequency. The source moves at a constant speed in a straight line relative to a stationary observer.
Which velocity of the source gives the smallest observed frequency?
What could describe the time-base of a cathode-ray oscilloscope (CRO)?
What happens when two waves superpose at a point?
An electromagnetic wave is diffracted as it passes through a single slit. The width of the slit is larger than the wavelength of the wave.
Which change will decrease the amount of diffraction of the wave?
The diagram shows visible light incident normally on a diffraction grating.
A pattern of intensity maxima forms on the screen. A line connecting the centre of the fourth order intensity maximum with the centre of the diffraction grating forms an angle of $53^{\circ}$ with the centre line. The grating has a line spacing of $2.7 \times 10^{-6}\,m$.
What is the wavelength of the incident light?
A horizontal glass tube, closed at one end, has a layer of dust laid inside it on its lower side. Sound is emitted from a loudspeaker that is placed near the open end of the tube.
The frequency of the sound is varied and, at one frequency, a stationary wave is formed inside the tube so that the dust forms small heaps.
The distance between four heaps of dust is 30 cm.
The speed of sound in the air in the tube is $330 \mathrm{ms}^{-1}$.
What is the frequency of the sound emitted by the loudspeaker?
There is a current in a resistor for a short time interval. Which statement about the total charge that passes through the resistor is correct?
The potential difference $V$ across a filament lamp is slowly raised from zero to its normal operating value.
Which graph represents the variation with $V$ of the current $I$ in the lamp?
An electric current of 12A is in a wire of length 0.35 m.
The average drift speed of the free electrons (charge carriers) in the wire is $5.0 \times 10^{-4} \text{ ms}^{-1}$.
How many free electrons are in the wire?
Three resistors are connected to a cell of negligible internal resistance.
Which circuit has a combined resistance of 100Ω?
Each of Kirchhoff’s laws is a statement based on the conservation of a physical quantity. Which quantity is conserved in each law?
[Table_1]
A cell with electromotive force (e.m.f.) 1.50 V delivers a current of 0.26 A to a resistor of resistance 5.0 \( \Omega \) connected between its terminals.
What is the internal resistance of the cell?
What is not a quark flavour?
How many down quarks are in a nucleus of hydrogen-3, $^3_1$H?
An isotope of boron decays to beryllium by $\beta^+$ emission.
Which particle is emitted in addition to the $\beta^+$ particle?