Question

a) When we see a car going by at 120 miles per hour we exclaim things like "That car is really going fast!", although it is really going at a constant speed. Why is it that if the accelerator pedal is very tight, the car is not going fast? Explain using Newton's laws.
b) Many times we think that what makes the car move is its engine. However, no matter how powerful the engine is (the energy it delivers per unit of time), the car cannot move if it is on a mud puddle, or on a pool of grease. Is it the engine, or is it the road that accelerates the car? Explain using Newton's laws.

Answer 1

a) The car is said to be moving fast when with rspect to is speed of car is much greater but to atain that much speed over a short period of time accelaartion provided would be higher so if accelator pedal would be very tight then then its inertia of state would be very high so you need more time to press it and accelation provided in short period would be less so speed of car is lesser and it is said to be not moving fast.

b) Yes car speed does depend on engine but energy due to engine is being provided in form rotatonal energy to the wheels of car so if you are in mud puddle pr pool of greese then friction between tyres and contact would become negligible so wheel do not roll over surface and they keep rotating over same contact and car will not move ahade so fricton between car and road playes key role to keep it moving on surface.