Speed = Distance/ Time
Speed = 400 / 4
Speed = 100 km/hr.
100 km per hour.
Newtons 1st law of motion states that the object will continue to move at its present speed and direction until an outside force acts upon it.
So unless the objects inside the car are restrained, they will continue moving at whatever speed the car is traveling at, even if the car is stopped by a crash.
Explanation:
What characteristics must the movement of a person have so that the value of the displacement is equal to the distance traveled?
Displacement is equal to the shortest path covered by an object. It is given by the difference of final position and the initial position.
Distance is equal to the total path covered by an object during the journey.
When an object moves in a straight line path, in this case, the displacement is equal to the distance traveled.
Motion of a ball thrown by a person upwards and caught after some time is an example of motion in which displacement of the particle is zero but acceleration is not zero in journey.
The displacement of the ball is zero because the starting and end point of the motion are same, i.e, the person's hands.During its motion, the acceleration of ball is constant and non zero called as acceleration due to gravity, g= -9.8 m/s². The velocity of ball is continuously changing. It first decreases during the upward motion of the ball and then increases during the downward journey.The acceleration remains constant and non zero all the time.