The car is traveling at a speed of 60 mi/hr as it approaches point A. Beginning

Question

The car is traveling at a speed of 60 mi/hr as it approaches point A. Beginning at A, the car decelerates at a constant 7 ft/sec^2 until it gets to point B, after which its constant rate of decrease of speed is 3 ft/sec^2 as it rounds the interchange ramp. Determine the magnitude of the total car acceleration (a) just before it gets to B, (b) just after it passes B, and (c) at point C.   

mean value of g and the mean value of the earth's radius. Also recognize that v is the magnitude of the velocity of the satellite with respect to the center of the earth.) The car is traveling at a speed of 60 mi/hr as it approaches point A. Beginning at A, the car decelerates at a constant 7 ft /sec2 until it gets to point B, after which its constant rate of decrease of speed is 3 ft/sec2 as it rounds the interchange ramp. Determine the magnitude of the total car acceleration (a) just before it gets to B, (6) just after it passes B, and (c) at point C.

Explanation / Answer

60 mi/hr = 88 ft/s

a) Magnitude of total car acceleration just before B = -7 ft/s^2 given

b) velocity at B is given byV^2 = u^2 -2aS

v^2 = 88^2 - 2*7*300

So, v = 59.5 ft/s

radial acceleration = v^2/r = 59.5^2/200 = 17.7 ft/s^2

tangential acceleration = -3 ft/s^2

total acceleration just after B = sqrt(17.7^2 + (-3)^2) = 17.97 ft/s^2

c) velocity at C is given by v^2 = 59.5^2 - 2*3*(pi*200/2)

v = 40.7 ft/s

radial acceleration = v^2/r = 40.7^2/200 = 8.28 ft/s^2

total acc = sqrt(8.28^2 + (-3)^2) = 8.8 ft/s^2

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.