9702_s15_qp_22
A paper of Physics, 9702
Questions:
7
Year:
2015
Paper:
2
Variant:
2
Login to start this paper & get access to powerful tools
2
A stone is thrown vertically upwards. The variation with time t of the displacement s of the stone is shown in . 1.0 s t / s 2.0 3.0 Use to describe, without calculation, the speed of the stone from t = 0 to t = 3.0 s. Assume air resistance is negligible and therefore the stone has constant acceleration. Calculate, for the stone, the speed at 3.0 s, speed = m s−1 the distance travelled from t = 0 to t = 3.0 s, distance = m the displacement from t = 0 to t = 3.0 s. displacement = m direction On , draw the variation with time t of the velocity v of the stone from t = 0 to t = 3.0 s. 1.0 v / m s–1 t / s 2.0 3.0
2. Kinematics  →  2.1. Equations of motion
Open
3
A rod PQ is attached at P to a vertical wall, as shown in . 0.64 m 0.96 m 30° P R wire wall rod Q W F The length of the rod is 1.60 m. The weight W of the rod acts 0.64 m from P. The rod is kept horizontal and in equilibrium by a wire attached to Q and to the wall at R. The wire provides a force F on the rod of 44 N at 30° to the horizontal. Determine the vertical component of F, vertical component = N the horizontal component of F. horizontal component = N By taking moments about P, determine the weight W of the rod. W = N Explain why the wall must exert a force on the rod at P. On , draw an arrow to represent the force acting on the rod at P. Label your arrow with the letter S.
4. Forces, density and pressure  →  4.2. Equilibrium of forces
4. Forces, density and pressure  →  4.1. Turning effects of forces
Open
4
A gas molecule has a mass of 6.64 × 10−27 kg and a speed of 1250 m s−1. The molecule collides normally with a flat surface and rebounds with the same speed, as shown in . molecule molecule before collision after collision flat surface flat surface Calculate the change in momentum of the molecule. change in momentum = N s Use the kinetic model to explain the pressure exerted by gases. Explain the effect of an increase in density, at constant temperature, on the pressure of a gas.
15. Ideal gases  →  15.3. Kinetic theory of gases
4. Forces, density and pressure  →  4.3. Density and pressure
Open
5
On , sketch the temperature characteristic of a thermistor. resistance temperature / °C A potential divider circuit is shown in . 12 V Z Y X The battery of electromotive force (e.m.f.) 12 V and negligible internal resistance is connected in series with resistors X and Y and thermistor Z. The resistance of Y is 15 kΩ and the resistance of Z at a particular temperature is 3.0 kΩ. The potential difference (p.d.) across Y is 8.0 V. Explain why the power transformed in the battery equals the total power transformed in X, Y and Z. Calculate the current in the circuit. current = A Calculate the resistance of X. resistance = Ω The temperature of Z is increased. State and explain the effect on the potential difference across Z.
10. D.C. circuits  →  10.3. Potential dividers
9. Electricity  →  9.3. Resistance and resistivity
Open
6
State two differences between progressive waves and stationary waves. 1. 2. A source S of microwaves is placed in front of a metal reflector R, as shown in . microwave detector D metal reflector R meter microwave source S A microwave detector D is placed between R and S. Describe how stationary waves are formed between R and S, how D is used to show that stationary waves are formed between R and S, how the wavelength of the microwaves may be determined using the apparatus in . The wavelength of the microwaves in is 2.8 cm. Calculate the frequency, in GHz, of the microwaves. frequency = GHz Please turn over for Question 7.
7. Waves  →  7.1. Progressive waves
8. Superposition  →  8.1. Stationary waves
Open