A horizontal net force is applied to a vehicle. Energy. Power. Question 1

Question. Source. Yahoo! Answers !

A horizontal net force of 2000 N is applied to a vehicle of mass 400 kg which is initially at rest on a horizontal surface. Determine ?

a. The acceleration of the vehicle.
b. The kinetic energy of the vehicle 5s after the force is first applied
c. The total power developed 5s after the force is first applied
Solution.

a) Newton’s Second Law F=m*a
So, a = F/m = 2000 / 400 = 5 m/s^2

b) V = Vi + a * t = 0 + 5*5 = 25 m/s
Ek = m * v^2 / 2 = 400 * 25^2 / 2 = 125000 J

c) P – Power = the change of the kinetic energy divided by time
P = (Ek – Eki) / t = 125000 / 5 = 25000 Watt

Thank you!

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s