Kinematics Acceleration physics homework

In summary, a motorist is driving at a steady speed when they have to brake suddenly to avoid a collision. The motorcycle decelerates at a rate of 7.0m/s2 and comes to a stop in 2.0s. To find the initial speed of the car, the distance it traveled during braking, and the total stopping distance, we can use equations related to kinematics such as the formula for acceleration (a = (vf - vi)/t) and the formula for distance (d = vit + 1/2at^2). It is also important to note that the driver took 7.0s to react and begin braking.
  • #1
space50
1
0
Physics help - I know that this qn may be easy but pls help!?

Homework Statement


A motorist was driving along a level road at a steady speed. He had to brake as quickly as possible to avoid a collision. The motorcycle decelerated uniformly at 7.0m/s2 and stopped in 2.0s.

a) At what speed was the car traveling before the breakes were applied?
b) How far did the car travel during braking?
c) If the driver took 7.0s between seeing the child and starting to brake, what was the total stopping distance of the car?
 
Physics news on Phys.org
  • #2


Any ideeas? equations? notes? bit of elbow grease? :P
 
  • #3


You will need to state some of the related equations. What equations have you learned related to kinematics that you think you can use in this problem?
 

1. What is acceleration in kinematics?

Acceleration in kinematics is the rate of change of velocity over time. It is a vector quantity, meaning it has both magnitude and direction, and is measured in meters per second squared (m/s^2).

2. How is acceleration calculated?

Acceleration can be calculated by dividing the change in velocity by the change in time. The formula for acceleration is a = (vf - vi) / t, where a is acceleration, vf is final velocity, vi is initial velocity, and t is time.

3. What is the difference between average and instantaneous acceleration?

Average acceleration is the overall change in velocity over a given time interval, while instantaneous acceleration is the acceleration at a specific moment in time. Average acceleration can be calculated using the formula mentioned in question 2, while instantaneous acceleration is calculated using calculus by finding the derivative of the velocity function.

4. How is acceleration related to other kinematic quantities?

Acceleration is related to other kinematic quantities through the equations of motion. For example, it is related to velocity through the formula vf = vi + at, and to displacement through the formula d = vit + 1/2at^2. These equations help us understand how acceleration affects an object's motion.

5. How is acceleration used in real life?

Acceleration is used in various real-life applications, such as in the automotive industry to measure a car's performance, in sports to analyze athletes' movements, and in space exploration to study the motion of objects in space. It also plays a crucial role in understanding the forces acting on objects and how they affect their motion.

Similar threads

Help with question on motion: Avoiding a rear-end collision
    • Introductory Physics Homework Help
Replies
6
Views
718
Minimum deceleration to prevent a collision
    • Introductory Physics Homework Help
Replies
33
Views
3K
Motion problem: motorist's braking time including reaction time
    • Introductory Physics Homework Help
Replies
1
Views
1K
Calculating Separation of Cars in a Convoy Moving at Max Speed
    • Introductory Physics Homework Help
Replies
4
Views
2K
Stopping distances on a downward slope
    • Introductory Physics Homework Help
Replies
3
Views
1K
Kinematics Problem: Train braking and blocking an intersection
    • Introductory Physics Homework Help
Replies
1
Views
937
Car Crash Analysis: Analyzing Friction & Speed
    • Introductory Physics Homework Help
Replies
9
Views
3K
Calculating Stopping Distance for Car Traveling at 3.0v
    • Introductory Physics Homework Help
Replies
1
Views
7K
Braking speed and distance traveled
    • Introductory Physics Homework Help
Replies
12
Views
2K
Stopping distance of a car?
    • Introductory Physics Homework Help
Replies
5
Views
1K

Hot Threads

Recent Insights

Back
Top