Acar is traveling with constant velocity along a highway. the driver notices he is late for work, so he stomps down on the gas pedal and the car begins to speed up. the car has just achieved double its initial velocity when the driver spots a police officer behind him and applies the brakes. the car then slows down, coming to rest at a stoplight ahead. draw a complete motion diagram for this situation.
part a
the car’s motion can be divided into three different stages: its motion before the driver realizes he’s late, its motion after the driver hits the gas (but before he sees the police car), and its motion after the driver sees the police car. which of the following simplifying assumptions is it reasonable to make in this problem?
a. during each of the three different stages of its motion, the car is moving with constant acceleration.
b. during each of the three different stages of its motion, the car is moving with constant velocity.
c. the highway is straight (i. e., there are no curves).
d. the highway is level (i. e., there are no hills or valleys).

c)

Explanation:

The highway is straight(i.e., there are no curves). If there is no curves in the path then it will be easier to study the motion of car.

Curves may include other forces like centripetal force which can make calculations more difficult.

Let car run with constant velocity for time , accelerate for time , decelerate for time

no sign of dia of fuel cell

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.