Physical Sciences – Trial Test

Physical Sciences – Trial Test 1. Copy and complete the statements below to compile a summary of this chapter. The missing words can be found in the list below. (a) Speed is a measure of the ………………………… at which an object moves over a distance. (b) ……………………………….. speed can be calculated by dividing the distance travelled by the time taken. (c) …………………………… is a measure of the rate of change in position. In order to describe the velocity fully, the ……………………… of the change in position must be stated. (d) The ………………………………. speed of an object is its speed at a particular instant of time. (e) The ……………………………… of an object moving in a straight line is a measure of the rate at which it changes speed. (f) The average acceleration of an object can be calculated by ………………………….. the change in its speed by the time taken for the change. (g) An object will remain at rest, or will not change its speed or direction unless it is acted upon by an outside, …………………………………… force. (h) The acceleration of an object depends on the mass of the object and the …………………….. force acting on it. (i) When an object applies a force to a second object, the second object applies an ………………. and ……………………………………… force to the first object. (j) All stored energy is called ……………………. energy (k) The Law of Conservation of Energy states that energy is never created or ………………………….. Average distance instantaneous Energy destroyed velocity Direction equal potential Unbalanced dividing change gravitational total weight work force acceleration opposite rate 2. Explain why the following statement is false. “A car travelling along a straight road has no forces acting on it.” 3. The table below provides information about four laps completed by one of the drivers in an Australian Formula One Grand Prix. The distance covered during one complete circuit of the course is 5.3 km. a. Make a copy of the table and fill in the empty cells. Lap no. Time (s) 5 90 15 Average speed (m/s) Average speed (km/h) 60 216 25 110 35 92 57.6 4. Complete these statements about Newton's Laws of Motion in your workbook. a. An object remains at rest, or will not change its speed or direction unless … b. When an unbalanced force acts on an object, the mass of an object affects … c. For every action, there is … 5. Explain in terms of Newton's First Law of Motion why it is dangerous to have loose objects inside a moving car. 6. Newton's Second Law of Motion can be expressed as the formula F = ma. What quantities do each of the symbols in the formula represent? 7. Use Newton's Second Law to calculate answers for the following. a. A 1400 kg car accelerates at 3 m/s2. What size force is needed to cause this acceleration? b. A force of 160 N causes an object to accelerate at 2 m/s2. What is the object's mass? c. A force of 210 N acts on a mass of 70 kg. What is the acceleration? 9. Classify the following as a type of potential energy or kinetic energy (use the letters K or P) (a) A bicyclist pedalling up a hill _____ (b) An archer with his bow drawn _____ (c) A volleyball player spiking a ball _____ (d) A baseball thrown to second base _____ (e) The chemical bonds in sugar _____ (f) The wind blowing through your hair _____ (g) Walking down the street _____ (h) Sitting in the top of a tree _____ (i) A bowling ball rolling down the alley _____ (k) A bowling ball sitting on the rack _____ Solve the following word problems using the kinetic and potential energy formulas Formulas: KE = 1 2 m v or PE = m·g·h 2 v = velocity or speed m = mass in kg g = 10 m/s/s h = height in meters 10. A baby carriage is sitting at the top of a hill that is 21 m high. The carriage with the baby has a mass of 1.5 kg. The carriage has _________________ energy. Calculate it. 11. A car is traveling with a velocity of 40 m/s and has a mass of 1120 kg. The car has _____________ energy. Calculate it. 12. A cinder block is sitting on a platform 20 m high. It weighs 7.9 kg. The block has _______________ energy. Calculate it. 13. A roller coaster is at the top of a 72 m hill and weighs 134 kg. The coaster (at this moment) has ____________ energy. Calculate it. 14. Determine the kinetic energy of a 1000-kg roller coaster car that is moving with a speed of 20.0 m/s. 15. If the roller coaster car in the above problem were moving with twice the speed, then what would be its new kinetic energy? 16. The potential energy of a 40-kg cannon ball is 14000 J. How high was the cannon ball to have this much potential energy? 17. Law of Conservation of Energy  Energy can be neither ______________ by ordinary means.  Energy can be ___________________ from one form to another.  The total amount of _________ is the _________ before and after any energy transformation. 18. Draw a free body diagram of the following scenarios: (a) An egg is free-falling from a nest in a tree. Neglect air resistance. Diagram the forces acting on the egg as it is falling. (b) A rightward force is applied to a book in order to move it across a desk with a rightward acceleration. Consider frictional forces. Neglect air resistance. Diagram the forces acting on the book.