Question

At what speed does a 1900 kg compact car have the same kinetic energy as a 1.7 x 10^4 kg truck going 25 km/hr?

Answer 1

it has to be in km/hr
I'm stuck on this one
please help!

Answer 2

E = 1/2 * m * v^2

E_truck = 0.5 * 1.7 * 10^4 [kg] * 25 [km/h]

calculate and set E_truck equal to E_car ... and calculate your speed (v) from that

Answer 3

oops

E_truck = 0.5 * 1.7 * 10^4 [kg] * 25 [km/h] * 25 [km/h] , of course ;>

Answer 4

mass of truck=1.7 x 10^4 kg
velocity of the truck=25km/hr=6.944 m/s


E(truck) = 1/2 * m * v^2=0.5*1.7*10^4*(6.944^2)
=4.099 × 10^5kgm^2/s^2
E(truck)=E(car)
Mass of compact car=1900 kg
E (car)=0.5*1900*V^2
0.5*1900*V^2=4.099 × 10^5
\[V^2= (\frac{4.099 × 10^5}{0.5*1900})\]
V=20.77m/s=74.772 km/h

Speed = approx 74.772 km/h