A sports car claims that it can start from rest and reach 60 mph(26.8 m/s) in a distance of 33.5 meters. To reach its maximummspeed, it accelerates at this constant rate for 11.25seconds.
a) How many seconds does it take to reach 60 mph?
- I got 1.25 seconds
b) What is the maximum speed of this car?
- Using kinematics I got 120.6 m/s
c) If the mass is 1900 kg, what force must the car provide to keepit traveling at this maximum speed ( Hint: don't forgetfriction)
- I know that Fnet= mass x acceleration, and that gives me 1900 x10.72 = 20,368 N
but this is not taking into account friction. What role doesfriction play and how can I calculate it properly?
d) I was driving this car at a maximum speed on a test track when adeer ran out in front of me. My reaction time was 0.5 seconds,before I hit the brakes. Assuming that the engine is no longerapplying any forward force, and my wheels lock up, how far will Itravel before I come to a stop after seeing the deer (give answerin miles, using: 1 Km = 0.62 miles)?
e) How much time will elapse from the time that I see the deeruntil I stop?
A sports car claims that it can start from rest and reach 60 mph(26.8 m/s) in a distance of 33.5 meters. To reach its maximummspeed, it accelerates at this constant rate for 11.25seconds.
a) How many seconds does it take to reach 60 mph?
- I got 1.25 seconds
b) What is the maximum speed of this car?
- Using kinematics I got 120.6 m/s
c) If the mass is 1900 kg, what force must the car provide to keepit traveling at this maximum speed ( Hint: don't forgetfriction)
- I know that Fnet= mass x acceleration, and that gives me 1900 x10.72 = 20,368 N
but this is not taking into account friction. What role doesfriction play and how can I calculate it properly?
d) I was driving this car at a maximum speed on a test track when adeer ran out in front of me. My reaction time was 0.5 seconds,before I hit the brakes. Assuming that the engine is no longerapplying any forward force, and my wheels lock up, how far will Itravel before I come to a stop after seeing the deer (give answerin miles, using: 1 Km = 0.62 miles)?
e) How much time will elapse from the time that I see the deeruntil I stop?
