Braking at a rate of 2.0 m/s each second sounds like a deceleration.r26h said:Homework Statement
A car comes to a stop in 7.5 meters while breaking at a rate of 2.0m/s each second.
Did you check the units of this calculation? I don't think 2.0 m/s per second multiplied by 7.5 meters will give an answer in secondsA) What was the initial speed of the car?
B) What is the speed of the car after 0.5 seconds?
Homework Equations
Final velocity = Initial velocity + acceleration*time
The Attempt at a Solution
A) 0=Initial velocity+(-2)(7.5)
Initial velocty = 15 m/s
B)0=15+(-2)(.5)
Velocity=14m/s
This equation requires the stopping time; you are told the stopping distance.. Final velocity = Initial velocity + acceleration*time
I guess you mean 7.5m/(2m/s), but you must not go plugging values into equations just because you know an equation that wants inputs of that type. You have to think about whether the equation is appropriate to the circumstance. What standard equation did you invoke to arrive at that calculation? What do the variables in the equation represent?r26h said:Ok, so what if to find the time I did 7.5m/ 2s/m = 3.75 seconds.
You are not asked for the time to stop, are you? But the equation you used will also tell you the speed after a given time.r26h said:To find the time, next I used Vf=Vi+at
0=5.48m/s +(-2m/s)(t)
-5.48m/s==2t
t=2.74s
Then which equation would I use to find the speed at 0.5 seconds?
The speed of a braking car is affected by several factors such as the weight of the car, the condition of the brakes, the road surface, and the coefficient of friction between the tires and the road. Other factors that can affect the speed of a braking car include the angle of the road, the weather conditions, and the driver's reaction time.
The weight of a car plays a significant role in its braking speed. A heavier car requires more force to stop due to its increased inertia. This means that it will take longer for a heavier car to come to a complete stop compared to a lighter car.
Yes, the condition of the brakes can greatly affect the speed of a braking car. Worn out brake pads or discs can decrease the friction between the brakes and the wheels, making it more difficult for the car to slow down or stop. It is important to regularly check and maintain the brakes to ensure safe and efficient braking.
The road surface can have a significant impact on the speed of a braking car. A rough or uneven road surface can decrease the friction between the tires and the road, making it harder for the car to slow down or stop. On the other hand, a smooth and dry road surface can provide better traction, allowing the car to brake more effectively.
The coefficient of friction is a measure of the amount of friction between two surfaces in contact. In the context of a braking car, it refers to the friction between the tires and the road. A higher coefficient of friction means more grip, which can help the car to come to a stop faster. However, the coefficient of friction can vary depending on the road surface and weather conditions, so it is important for drivers to adjust their braking accordingly.