Kinematics - Physics question?

Question

An engineer decides to design a runway to accomodate flying squirrels. To take off, the squirrels must attain a ground speed of 10m/s. If they can accelerate at the rate of 1.5m/s^2.

a)How long will it take the squirrels to reach this velocity.

b)What must be the minimum length of the runway?

Please give me a step-by-step explanation. Thanks!

Answer 1

This one sounds tricky, but if you separate the given and have a look at what you need for each question, it's easy as pie.

Given:

Initial velocity: 0m/s

Final velocity: 10m/s

Acceleration: 1.5m/s^2

Time: We don't know

Distance: we don't know

a) We need an equation for time. We know that:

V2 = V1 + a*t

Which means that:

t= (V2 - V1) / a

All you have to do is sub in the givens to solve for time.

b) We need an equation for distance. We know:

d = V1*t + 1/2*a*t^2

Since we know time, we can easily solve for distance.

The equations you use in class may be different from mine. If so, all you have to do is approach it systematically, look for equations that contain the given variables.

Good luck with your problem!