Answer:
v = 60.62 km/h
Explanation:
Kinetic energy
Kinetic energy is that which is due to the movement of bodies and is calculted like this:
K = (1/2)mv² Formula (1)
Where:
K : Kinetic energy (J)
m: mass (kg)
v : speed (m/s)
Data for the truck
m = 15000 kg
v= 21 km/h = 21 *(1000m)/ (3600s)
v= 5.83 m/s
Calculation of the kinetic energy of the truck
We replace data in the formula (1)
K = (1/2)mv²
K = (1/2)(15000)(5.83)²
K = 255208.3 J
Data for the compact car
K = 255208.3 J = 255208.3 (N*m)
m = 1800 kg
Calculation of the speed of the compact car
We replace data in the formula (1)
K = (1/2)mv²
255208.3 = (1/2)( 1800)(v)²
255208.3 = ( 900)(v)²
v² = 255208.3 / ( 900)
[tex]v= \sqrt{\frac{255208.3}{900} }[/tex]
v = 16.84 m/s
1 km = 1000 m
1 h = 3600 s
v = 16.84*(3600/1000)km/h
v = 60.62 km/h
