Solving Acceleration Problem: Find m/s^2 & Seconds

[bwilhelm]

1. A plane traveling at 10km/hr lands on an aircraft carrier and stops in 25.0m
A. Find the acceleration in m/s^2
B. Find the time it took to stop in seconds

Homework Equations

1km/hr = .278 m/s

The Attempt at a Solution

100(.278)= 27.8 m/s
A. 25-27.8 = 2.8 m/s
B. 8.92 seconds (25/2.8)

Is this anywhere near correct? something seems wrong.

 

[learningphysics]

1. A plane traveling at 10km/hr lands on an aircraft carrier and stops in 25.0m
A. Find the acceleration in m/s^2
B. Find the time it took to stop in seconds

Homework Equations

1km/hr = .278 m/s

The Attempt at a Solution

100(.278)= 27.8 m/s
A. 25-27.8 = 2.8 m/s
B. 8.92 seconds (25/2.8)

Is this anywhere near correct? something seems wrong.

When you converted to m/s you used 100km/h instead of 10km/h.

I don't understand how you did part A and B... seems like you're mixing up distance, speed and acceleration.

Remember the plane is undergoing a constant deceleration (or a negative acceleration) and coming to a stop over 25m.

Part A and B involve direct use of kinematics equations... you should have studied these... Can you think of a kinematics equation you can apply in part A? You're trying to find acceleration... you know the distance, the initial velocity, and the final velocity. There's an equation you can use.

 

[Dick]

Not near correct. 27.8 m/s is ok, though. Consider using kinematic equations like x(t)=x0+v0*t+(1/2)*a*t^2 and v(t)=v0+a*t. Can you start the problem?