The Kentucky Derby is one of the most exciting horse races run every year. In 1973, the horse Secretariat set a record that still stands. This 500-kg horse ran the 2000-m track in 120 s. What was Secretariat's average kinetic energy? (1 kJ = 1000 J)

69.44kJ

Explanation:

Kinetic energy is expressed as;

KE = 1/2mv^2

m is the mass = 500kg

v is the velocity

Get the velocity;

v = displacement/time

velocity = 2000/120

velcoity = 16.7m/s

Gt the kinetic energy

KE = 1/2 * 500 * 16.7²

KE = 250*277.78

KE = 69,444.4Joules

Since 1000J = 1kJ

69,444.4Joules = 69,444.4/1000

69,444.4Joules = 69.44kJ

Hence the Secretariat's average kinetic energy is  69.44kJ

b.

explanation:

10.0

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s