1) car a has a mass of 1,000 kg and is traveling 60 km/hr. car b has a mass of 2,000 kg and is traveling 30 km/hr. compare
Question:
car a has a mass of 1,000 kg and is traveling 60 km/hr. car b has a mass of 2,000 kg and is traveling 30 km/hr. compare the kinetic energy of car a with that of car b?
a) equal
b) half as much
c) twice as much
d) four times as much
Answers
C
Explanation:
Calculate EkA -kinetic energy of car A
m=1000kg
Va=16.66 m/s
EkA=m*Va²/2
Eka=(1000kg*277.556m²/s²)/2
Eka=138 777.8 J
Calculate kinetic energy of CarB:
m=2000 kg
Vb=8.33 m/s
Ekb=(m*Vb²)/2
Ekb=(2000kg*69.39m²/s²)/2
Ekb=69 388.9 J
compare Eka with EkB
Eka/Ekb=138 777.8 J/69 388.9
Eka/Ekb=2
c) Twice as much
Explanation:
As we know that kinetic energy is given by the formula
[tex]K = \frac{1}{2}mv^2[/tex]
here we know that
m = mass of the object
v = speed of the object
so here we will have kinetic energy of Car A
[tex]K = \frac{1}{2}(1000)(60^2)[/tex]
[tex]K_a = 1.8 \times 10^6[/tex]
now we have kinetic energy of B is given as
[tex]K_b = \frac{1}{2}(2000)(30^2)[/tex]
[tex]K_b = 0.9 \times 10^6[/tex]
So kinetic energy of Car A is double that of Kinetic energy of car B
twice as much
Explanation:
Using the formula for the amount of kinetic energy: K.E. = 1/2 m v2. You would find that car A has twice as much energy as car B.