# Mass, speed, and force to find new speed and distance traveled during period.

• keevo
In summary: Also, the value you got for V is incorrect. Instead, use the initial velocity of 27.611 m/s and the acceleration of 0.192 m/s^2 to solve for the final velocity after 26.9 seconds of braking. Once you have the final velocity, you can use the third equation to solve for the distance traveled during this time period. Remember to convert the units to km. In summary, the train's initial mass is 5,770,000 kg and its initial speed is 99.4 km/hr (or 27.611 m/s). After 26.9 seconds of braking with a net backward force of 1,110,000 N, the train's new speed can be
keevo
. Homework Statement

A train has a mass of 5.77E+6 kg and is moving at 99.4 km/hr. The engineer applies the brakes, which results in a net backward force of 1.11E+6 N on the train. The brakes are held on for 26.9 s.

What is the new speed of the train?

How far does it travel during this period?

mass of train: 5,770,000 kg

speed of train: 99.4 km/hr (i converted it to m/s and got 27.611 m/s)

Backwards net force of: 1,110,000 N

Brakes held for: 26.9 s

2. Homework Equations

f=ma?

V=Vo+at?

X=Xo+(Vo)(t)+.5at^2?

3. The Attempt at a Solution

I am fairly new to physics and don't really know what I'm doing, anyways...first i used f=ma
and got a=.192 then i used that in the second equation and got V=1,110,005.165 N and then I plugged that into the third equation and got 29859069.4666 M but it said i was wrong :/.

I am not asking for the answer, just what equations to use and what order to do what in, of coarse if you would like to solve it for me feel free:)

Last edited by a moderator:
Try to work with units, it helps spotting errors in your calculations.
Your 3 equations are correct, and can be used to solve the problem.

V=1,110,005.165 N
??
V in your second equation is a velocity, not a force.

## 1. How do mass, speed, and force affect an object's new speed and distance traveled?

Mass, speed, and force are all related to an object's acceleration. The greater the mass of an object, the more force is needed to accelerate it. Similarly, the faster an object is moving, the more force is needed to change its speed. Therefore, the final speed and distance traveled of an object are determined by its mass, initial speed, and the force applied to it.

## 2. What is the relationship between mass and acceleration?

According to Newton's Second Law of Motion, the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass. This means that as the mass of an object increases, its acceleration decreases, and vice versa.

## 3. How does speed affect an object's acceleration?

Speed and acceleration are directly related. The greater the speed of an object, the greater the acceleration will be when a force is applied to it. This is because a larger force is required to change the speed of a faster-moving object compared to a slower-moving object.

## 4. Can you use mass, speed, and force to calculate the new speed and distance traveled of an object?

Yes, using Newton's Second Law of Motion (F=ma) and the equations for calculating speed (v=d/t) and distance (d=vt), you can determine the new speed and distance traveled of an object when given its initial mass, speed, and the force applied to it.

## 5. What are some real-life examples of using mass, speed, and force to find an object's new speed and distance traveled?

Calculating the speed and distance of a car when applying the brakes or accelerating, determining the trajectory of a projectile such as a ball thrown or a rocket launched, and predicting the speed and distance of an object rolling down a hill are all examples of using mass, speed, and force to find new speed and distance traveled during a period.

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