- #1
cherryrocket
- 19
- 0
7.Q: "Nancy was riding in a helicopter which was rising at 4.0 m/s when she dropped her camera out. After 2.0 s how far apart were the camera and the helicopter?"
A: This isn't an acceleration question is it? Just velocity?
d=vt = (4.0m/s)(2.0s) = 8.0m
8.Q: "A certain car tire can accelerate a car to a stop at a maximum rate of -11.2 m/s^2".
A driver going at 90.0 km/h sees a hole 30.0m ahead and hits the brakes. How far does it take the car to stop? Does the car hit the hole? Assume a reaction time of zero seconds."
A:
a = -11.2 m/s^2
v = 90.0 km/h = 24.993 m/s = 25.0 m/s
t=v/a = 25.0m/s / -11.2 m/s^2 = 36.2s
d=vt = 25.0m/s / (36.2s) = 0.691 m
"The car stops 0.691 m later, so no it does not hit the hole." Is this correct?
A: This isn't an acceleration question is it? Just velocity?
d=vt = (4.0m/s)(2.0s) = 8.0m
8.Q: "A certain car tire can accelerate a car to a stop at a maximum rate of -11.2 m/s^2".
A driver going at 90.0 km/h sees a hole 30.0m ahead and hits the brakes. How far does it take the car to stop? Does the car hit the hole? Assume a reaction time of zero seconds."
A:
a = -11.2 m/s^2
v = 90.0 km/h = 24.993 m/s = 25.0 m/s
t=v/a = 25.0m/s / -11.2 m/s^2 = 36.2s
d=vt = 25.0m/s / (36.2s) = 0.691 m
"The car stops 0.691 m later, so no it does not hit the hole." Is this correct?