The braking distance of a car is directly proportional to te square of it's speed.
When the speed is p metres per second, the braking distance is 6m. When the speed is increased by 300%, find
(a) an expression for speed of the car
(b) the braking distance
(c) the % increase in the braking distance
Is there any fixed methods for this type of question? Thanks a lot!!! :)))))))
 👍
 👎
 👁
 ℹ️
 🚩
2 answers

How did you find new speed?
 👍
 👎
 ℹ️
 🚩
answered by Nikez 
d = k v^2 so v = sqrt(d/k)
6 = k p^2 so p = sqrt (6/k)
new speed = 4 p = 4 sqrt (6/k)
new d = k v^2 = k*16(6/k) = 96 meters
96/6 = 16 times = 1600 %
or
new speed = 1600 percent of old speed
so
percent increase = 1600100 = 1500% increase 👍
 👎
 ℹ️
 🚩
answered by Damon
Answer this Question
Related Questions

PRECALC still stuck
Write the statement as a power function equation. Use k for constant of variation if one is not given. a. Charles's law states the volume V of an enclosed ideal gas at a constant pressure varies directly as the absolute temperature T. b. The volume V of a
 asked by Muffy
 2,467 views

Physics !!Check Answers!!
1. What happens to the gravitational force between two objects if the distance between them triples? A. The force increases by a factor of 3 B. The force decreases by a factor of 9 C. The force increases by a factor of 9 D. The force decreases by a factor
 asked by Jamie
 5,510 views

math
The stopping distance d of a car after the brakes have been applied varies directly as the square of the speed r. If a car traveling 40 mph can stop in 100 ft, how fast can a car travel and still stop in 256 ft?
 asked by tevita
 7,886 views

Physics
You are driving down the highway late one night at 20 m/s when a deer steps onto the road 35 m in front of you. Your reaction time before stepping on the brakes is 0.50 s , and the maximum deceleration of your car is 10 m/s2 . How much distance is between
 asked by Harvey
 9,853 views

physics
What is the work done by a car's braking system when it slows the 1500kg car from an initial speed of 96 km/h down to 56 km/h in a distance of 55 m? I have tried to work this one and can't seem to get the answer.
 asked by merri
 2,198 views

physics
You testify as an expert witness in a case involving an accident in which car A slid into the rear of car B, which was stopped at a red light along a road headed down a hill (see the figure). You find that the slope of the hill is θ = 14.0°, that the
 asked by kristy
 7,331 views

math
(TRANSPORTATION COST) A truck is hired to transport goods from a factory to a warehouse. The driver’s wages are figured by the hour and so are inversely proportional to the speed at which the truck is driven. The cost of gasoline is directly proportional
 asked by m.h.j
 565 views

Physics
A car moving at some speed hits the brakes and skids to a stop after 11 m on a level road. If the coefficient of friction for the road conditions of wet asphalt is 0.53, what was the car's original speed before braking? I have used multiple modes to find
 asked by Kirstie
 842 views

physics 1
In coming to a stop a car leaves skid marks 92m long on the highway. Assuming a decceleration of 7.00m/s^2, estimate the speed of the car just before braking.
 asked by john
 13,357 views

Physics
A car accelerates in the +x direction from rest with a constant acceleration of a1 = 1.76 m/s2 for t1 = 20 s. At that point the driver notices a tree limb that has fallen on the road and brakes hard for t2 = 5 s with a constant acceleration of a2 = 5.93
 asked by Uwais
 8,602 views

Physics
A car starts from rest and travels for 10 seconds with a constant acceleration of 3.0 m s^2. The driver then applies the brakes causing a negative acceleration of 4.0 m s^2. Assuming that the brakes are applied for 2.0 seconds, calculate, a) the
 asked by Katherine .Mk
 865 views

Math
The illumination of an object by a light source is directly proportional to the strength of the source and inversely proportional to the square of the distance from the source. If two light sources, one four times as strong as the other, are placed 11 ft
 asked by Alex
 1,837 views

physics
A force of 9000 N is used to stop a 1500kg car traveling at 20 m/s. What braking distance is needed to bring the car to a halt?
 asked by Bobbie
 3,947 views

Physics Urgent!
1.You are driving at the speed of 28.7 m/s (64.2138 mph) when suddenly the car in front of you (previously traveling at the same speed) brakes. Considering an average human reaction, you press the brakes 0.427 s later. Assume that the brakes on both cars
 asked by Mikayla
 5,831 views

math
it is given that y is directly proportional to xn. write down the value of n when (i) y m square is the area of a square length x m . (ii) y cm cube is the volume of a cube of length x cm.
 asked by nurul
 7,171 views

physics
Cars A and B are racing each other along a straight path in following manner: Car A has head start and is a distance dA beyond starting line at t=0. The starting line is at x=o. Car A travels at constant speed vA. Car B starts at starting line but has
 asked by help
 10,877 views

Physics answer check pls
1. The electrostatic force between two charges is originally F. Which expression represents the new electrostatic force between the two charges if one charge doubles and the other one is divided by three? A. 3/2 F B. 2/3 F C. 1/6 F D. 6 F 2. Suppose the
 asked by Brad
 3,686 views

Physics
I really cannot understand how to get to the answer. Thank you! Two cars are traveling, Car A is behind the other, on a straight road. Each has a speed of 21 m/s and the distance between them is 25 m. The driver of the rear car decides to overtake the Car
 asked by Darius
 2,071 views

physics
A 2172.5 kg car is coasting along a level road at 34.7 m/s. A constant braking force is applied,such that the car is stopped in a distance of 50.5 m. What is the magnitude of the braking force? Answer in N. Here is my way, but im not sure if im correct:
 asked by alexa
 4,722 views

Physics
A driver in a car, originally moving at 13.1 m/s, applies the brakes until the car comes to a stop. The car moves a distance of 34.1 m while braking. How much time did it take for the car to stop? Assume constant acceleration during braking.
 asked by Kate
 1,698 views
Still need help?
You can ask a new question or browse existing questions.