Physics Paper 1 Questions and Answers - Sunrise Pre Mock Exams 2023

INSTRUCTIONS TO CANDIDATES

• This paper consists of 12 questions.
• Answer ALL the questions in the spaces provided.
• ALL working MUST be clearly shown.
• ALL numerical answers MUST be expressed in decimal forms.

SECTION A (25 MARKS)

Answer all the questions in this section in the spaces provided.

1. The Figure below shows part of a scale of vernier calipers. What is the reading indicted by the scale? (2 marks)
   
2. The Figure shows two match sticks placed on water in a basin a few centimeters apart.
   
   State and explain the observation made when a drop of soap solution is placed at a point marked x. (2 marks)
3. When a body of mass 0.35kg is acted upon by a force, its velocity changes from 3.5m/s to 6.0m/s.Determine the power developed by the force. (2marks)
4. Figure below shows a uniform rod 4m long and of mass 2kg. It is pivoted 1m from one end and balanced horizontally by a string attached near the other end.
   
   Determine the position where a mass of 5kg should be placed on the rod so that the rod remains horizontal and the tension in the string is zero. (3 marks)
5. Water flows steadily along a horizontal pipe at a volume rate of m³/s. if the area of cross-section of the pipe is 20cm² . Calculate the velocity of the fluid.     (2marks)
6. State any two states of equilibrium. (2 marks)
7. A ball is thrown from the top of a cliff 20m high with a horizontal velocity of 10ms^-1 . Calculate the distance from the foot of the cliff to where the ball strikes the ground. (3 marks)
8. Explain one advantage of mercury over alcohol as a thermometric liquid.    (1mark)
9. A body of mass M is allowed to slide down an inclined plane. State two factors that affect its final velocity at the bottom of the inclined plane. (2marks)
10. For an enclosed system with a liquid, a force is applied at one point.
    1. Briefly explain how force is transmitted to other parts of the system. (1 marks)
    2. State one application of such a system. (1 marks)
11. A 150g mass tied on a string is whirled in a vertical circle of radius 30cm with a uniform speed. At the lowest position the tension in the string is 9.5N, Calculate the velocity of the mass. (2 marks)
12. A spring of elastic constant K has its length increased from 4.00m when unloaded to 4.25m when loaded with a 75N weight. Assuming that the elastic limit is not exceeded, determine the value of K. (2 marks)

SECTION B: 55 MARKS

13.  
    1. Sketch a block and tackle pulley system with three movable pulleys in the lower block and two fixed pulleys in the upper block. (2marks)
    2. Find:
       1. Velocity ratio (V.R.).  (1mark)
       2. An effort of 450 N is used to raise a load of 2700N.Determine:
          1. Mechanical advantage (M.A) (2marks)
          2. Efficiency of the pulley system. (2marks)
       3. All the wasted energy is used to raise the lower block and to overcome frictional force between the pulleys and moving parts; determine the weight of the lower block if the frictional force is 3.6N. (2marks)
    3. If the load moved through a distance of 50cm, determine the useful work done by the effort. (2marks)
    4. John applied a force of 400N in pushing a stationery wall. If he took one hour to push the wall, calculate the power developed. (1mk)
14.  
    1. State two factors that affect the boiling point of a liquid (2 marks)
    2. 100g of a liquid at a temperature of 10°C is poured into a well lagged calorimeter. An electric heater rated 50W is used to heat the liquid. The graph in figure shows the variation of the temperature of the liquid with time.
                 
       
       1. From the graph, determine the boiling point of the liquid (1 mark)
       2. Determine the heat given out the by the heater between the times t = 0.5 minutes and t = 5.0 minutes (2 marks)
    3. From the graph determine the temperature change between the times t = 0.5 minutes and t = 5.0 minutes, hence determine the specific heat capacity of the liquid. (3 marks)
    4. 1.8 g of vapor was collected from above the liquid between the times t= 3.5 minutes and t= 4.5 minutes. Determine the specific latent heat of vaporization of the liquid. (3 marks)
15.  
    1. Define “absolute zero temperature” for an ideal gas (1 mark)
    2. Using kinetic theory, explain Boyle’s law for an ideal gas. (2marks)
    3. The diagram shows an experiment to investigate the relationship between volume and temperature of a fixed mass of gas at constant pressure.
       
       
       1. Explain the function of;
          1. Concentrated sulphuric acid (1 mark)
          2. Stirrer (1 mark)
       2. Explain how the set up above can be used to verify Charles law for an ideal gas (3marks)
       3. On the grid below sketch a graph of volume (cm 3 ) against temperature ( 0 c). Mark with letter T the absolute zero temperature. (2 marks)
    4. A column of air 20cm long is trapped by mercury thread 6cm long as shown in figure below.
       
       If the tube is now inverted, determine column X in figure b).Take atmospheric pressure as 76cm of mercury. (2marks)
16.  
    1. State the law of floatation (1 mark)
    2. Figure below shows a simple hydrometer
       
       
       1. Identify the parts labelled A and B (2 marks)
       2. State the purpose of the part labelled B (1 mark)
    3. How would the hydrometer be made more sensitive? (1 mark)
    4. Describe how the hydrometer is calibrated to measure relative density. (3 marks)
    5. Figure shows a cork floating on water and held to the bottom of the beaker by a thin thread.
       1. Name the forces acting on the cork (2 marks)
          
       2. Describe how each of the forces mentioned in(i) above changes when water is added until the container is completely filled (2 marks)
17.  
    1.  
       1. What is meant by perfectly inelastic collision. (1 mark)
       2. A minibus of mass 1600kg travelling at a constant velocity of 20mls collides with a stationary car of mass 800kg. The impact takes 2seconds before the two moves together and come to rest after 15seconds. Determine.
          1. The common velocity. (3marks)
          2. The distance moved after the impact. (2 marks)
       3. The impulse force. (2 marks)

MARKING SCHEME

SECTION A

1. Main scale reading = 3.20 cm
   Vernier scale reading = 0.05 cm ✓¹ for both readings
   Reading on the scale = 3.25 cm.  ✓¹
2.  
   • Match sticks moves away from each other ✓¹
     
   • Soap solution weakens surfaces tension in between hence stronger force on pulls them outwards ✓¹
3. P=F∆V✓ =3.5×(6.0-3.5) = 8.75W✓
4. f₁d₁ = f₂d₂
   20 × 1.0 = d₂ × 50
   ²⁰/₅₀ = 0.4m
5. Flow_ rate = A × speed
   8 × 10⁻³ m³/s =     20     × v
                                10000
   v = 8 × 10¯³ × 10000
                     20
   v = 4m/s
6.  
   • Neutral
   • Unstable
7. h = ½gt² = 20 = ½ × 10× t² → t = 2 seconds; award for time
   R = ut → R = 10 × 2; = 20m formula/sub and the correct answer with units
8. Higher boiling point so it can measure higher temperature than alcohol;
9.  
   • Angle of inclination of the plane
   • Vertical Height of the inclined plane
   • Length of the plane
   • Frictional force between the plane and the body
     Maximum of two marks but consider only the first two responses of the learner
10.  
    1. Pressure is developed at the point of application of the force. ✓1Since the liquid is incompressible, pressure is uniformly transmitted and force is generated.✓1
    2. Hydraulic machines (brakes, press,lift)✓1
11. F= mv² + mg  ✓1
           r
    9.5 =  150  ×    v2     + 150  × 10  ✓1
             1000    ³⁰/₁₀₀      1000
    V² = 8.0 × 1000 × 30 =16
               150 × 100
    V=4.00m/s  ✓1
12. e = 4.25 − 4.00 = 0.25m
    F = Ke
    75 = 0.25k  ✓1
    K = 300N/m ✓1

SECTION B

13.  
    1.   
       
    2.  
       1. V.R =Number of the ropes supporting the load = 6
       2.  
          1. M.A = L = 2400 = 5.333
                        E     450
          2. Efficiency of the pulley system.  
             M.A × 100% =
              V.R
             5.333 × 100% = 88.88%
                 6                                                  
       3. Wasted effort = 11.12 × 450 = 50.04N
          Wasted effort = Weight of lower block + Frictional Force
          Weight of lower block = 50.04 − 3.6N = 46.44N
    3. Load = Load distance = 2400 × 0.5 = 1200J
    4. Power = work done = 400 × 0 = 0J
                         time             3600
14.  
    1.  
       • Impurities;
       • Pressure;
    2.  
       1. 80⁰C    ;
       2. time = (5 − 1.5) × 60 = 210 seconds;
          heat(energy) = power × time = 50 × 210; = 10500J; 
    3. Change in temperature = 80 − 20 = 60°C    ;
       Heat energy absorbed = mcΔθ → 10500 = 0.1 × c × 60 ;formula or substitution
       c = 10500   = 1750J/kg K ;     correct answer with units
             0.1×60
    4. Heat energy supplied by the heater = heat energy spent to vaporize the liquid         ;
       mL_v = 50 × 1 × 60; correct substitutions for both energy supplied and absorbed
       L_v = 3000 = 30000J/kg; correct answer with correct units
                 0.1
15.  
    1. The temperature at which the volume/ pressure/K.E of a gas is assumed to be zero.✓1
    2. Reducing the volume increases the number of collisions of gas particles with the walls of the container per unit time.✓1Therefore the rate of change of momentum will also increase leading an increase in pressure.✓1
    3.  
       1.  
          1.  
             • Serves as a pointer to the volume on scale or
             • To trap the gas in the tube or
             • A drying agent for the gas✓1
          2. To make the temperature of the bath uniform✓1
       2. Heat the bath and record the temperature and height/volume of air trapped at suitable temperature interval.✓1 Plot  a graph of volume/height against temperature.✓1 The graph is a straight line indicating proportional change in volume and temperature✓1
       3. See sketch on grid.
          
    4. P₁V₁=P₂V₂ 
       (76 + 6 )(20) = (76 − 6)x  ✓1
       X = 82 × 20 = 23.429cm ✓1
                  70
16.  
    1. A floating body displaces its own weight of fluid in which it floats;
    2.  
       1.  
          1. A          bulb     ;
          2. B          lead-shots        ;
       2. It enables the hydrometer float upright    ;
    3. Using a narrower glass-stem  ;
    4.  
       • Float the hydrometer in a liquid of known relative density and mark level of the liquid on the stem;
       • Float the hydrometer again in another liquid of known relative density and mark its level on the stem;
       • Divide the length between the marks into equal divisions and label it accordingly  ;
    5.  
       1.  
          • Tension;
          • Up-thrust;
          • Weight;
       2.  
          • Tension increases;
          • Up-thrust increases;
          • weight remains constant              
17.  
    1.  
       1. collision where only linear Momentum is conserved and bodies moves together after collision (coelesce).
       2.  
          1. Momentum before collision = Momentum after collision
             (1600 x 20) + (800 x 0) = (1600 + 800)V
             V = 32000 = 13.33m/s
                     2400
          2. V = U + at
             ⇒ 13.33 + 15a ⇒ pa     = −0.89m/s²
             V² = U² + 2as ⇒ S = V² − U² = 0 − (13.33)²
                                                  2a         −2(0.89)
                                           = 99.83m
       3. Impulse tone = ΔP = 1600(20 − 13.33) for minibus
                                                         2
                                         = 5336N
                            Or  800(13.33 − 0) for a car
                                            2
                                           = 5336N.