Question

In a recent movie, a car and a truck had a head on collision. The car was moving to the right with a constant speed of 21 m/s. A parked truck that was 310 m in front of the car began moving to the left and speeding up at a rate of 1.2 m/s/s. Position 0 m is the car's initial position.

What is the position of the car after 4 seconds?
What is the position of the truck after 4 seconds?
What is the velocity of the truck upon impact with the car?
How much time passes before the collision happens?
Where do the car and truck collide?

Answer 1

Answer:To solve this problem, we need to use the equations of motion and kinematics.

1. What is the position of the car after 4 seconds?

The position of the car after 4 seconds can be found using the equation:

position = initial position + (initial velocity x time) + (1/2 x acceleration x time^2)

Plugging in the values, we get:

position = 0 + (21 x 4) + (1/2 x 0 x 4^2) = 84 meters

Therefore, the position of the car after 4 seconds is 84 meters.

2. What is the position of the truck after 4 seconds?

The position of the truck after 4 seconds can be found using the equation of motion for uniform acceleration:

position = initial position + (initial velocity x time) + (1/2 x acceleration x time^2)

Initial velocity of the truck is zero, and the acceleration is 1.2 m/s^2. The initial position of the truck is 310 meters ahead of the car.

Plugging in the values, we get:

position = 310 + (0 x 4) + (1/2 x 1.2 x 4^2) = 326.4 meters

Therefore, the position of the truck after 4 seconds is 326.4 meters.

3. What is the velocity of the truck upon impact with the car?

To find the velocity of the truck upon impact with the car, we need to use the equation:

final velocity = initial velocity + acceleration x time

The initial velocity of the truck is zero, the acceleration is 1.2 m/s^2, and the time is the time it takes for the collision to happen.

4. How much time passes before the collision happens?

To find the time it takes for the collision to happen, we need to use the equations of motion and kinematics.

The position of the car at the time of the collision is the same as the position of the truck at the time of the collision. Let's call this position "x".

Using the equation of motion for the car, we have:

x = 0 + (21 x t) + (1/2 x 0 x t^2) = 21t

Using the equation of motion for the truck, we have:

x = 310 + (0 x t) + (1/2 x 1.2 x t^2) = 0.6t^2 + 310

Setting these two equations equal to each other, we get:

21t = 0.6t^2 + 310

Simplifying and solving for t, we get:

t = 23.98 seconds

Therefore, the time it takes for the collision to happen is approximately 24 seconds.

5. Where do the car and truck collide?

The position of the collision can be found by plugging the time into either the equation of motion for the car or the equation of motion for the truck.

Using the equation of motion for the car:

position = 21 x 23.98 = 503.58 meters

Using the equation of motion for the truck:

position = 0.6 x (23.98)^2 + 310 = 503.58 meters

Therefore, the car and truck collide at a position of 503.58 meters.

Step-by-step explanation: