Ram is a college student in Delhi. Ram and his family are going by car to visit a hill station. Ram himself is driving the car. Ram drives the car very carefully. Before starting to drive, Ram has fastened the car seat belt himself properly. He has also made his father, mother and younger brother fasten their car seat belts. on the flat highwat road, Ram is keeping the car speed within a range of 50 to 60 kmph (which is well within the prescribed speed limit on this highway). He does nto accelerate the car unnecessarily. After driving for about five hours continuously on a flat road, there is a sight of hills in view. On approaching the hilly road, Ram increases the speed of his car. Ram's younger brother Anish, who is a student of class VI, is surprised to see his brother increasing the speed of car suddenly. Anish asks Ram why the speed of car has been increased. Ram explains the reason for increasing the speed of car to everyone.
(a) What type of energy is possessed by the car while running on the flat road?
(b) What type of energy transformation take place in a car engine?
(c) When the car is moving on the flat road, it has to do work to overcome mainly two types of forces. Name these two types of forces.
(d) When the car is moving on an uphill road, it has to do work to overcome three types of forces. Name these three types of forces.
(e) Why does Ram increase the speed of his car on approaching the hilly road?
(f) What types of energy is possessed by the car going up on the hilly road?
(g) What values are displayed by Ram in this episode?

Explanation

(a) The car running on a flat road possesses 'kinetic energy'.
(b) The car burns petrol as fuel. The car engine first converts the chemical energy of petrol into heat energy. This heat energy is then converted into kinetic energy (which drives the wheels of the car). The transformation of energy taking place in a car engine can be written as:
`underset(("of petrol"))("Chemical energy")rarr"Heat energy"rarr"Kinetic energy"`
(c) When the car is moving on a flat road, it has to do work to overcome (i) friction of the road, and (ii) air resistance.
(d) When the car is moving on an uphill road, then it has to do work to overcome (i) friction of the road (ii) air resistance, and (iii) force of gravity.
(e) Ram increases the speed of car on approaching a hilly road to give more kinetic energy to the car so that it may go up the hill aganist gravity.
(f) The car going up on the hilly road possesses (i) kinetic energy, and (ii) gravitational potential energy.
(g) The various values displayed by Ram in this episode are (i) Concern for the safety of his family (as shown by the fastening of car seat belts and driving within speed limit) (ii) Conservation of fuel or petrol (by driving the car within a specified speed range and avoiding unnecessary accelerating) (iii) Awareness (that car needs more kinetic energy to go up on a hilly road), and (iv) Knowledge (that kinetic energy of car can be increased by increasing its speed).