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1. A sprinter runs at a forward velocity of 11.9m/s. If the sprinter has a mass of 77.4kg, what is the sprinter’s kinetic energy?




2. A car having a mass of 654kg has a kinetic energy of 73,700J. What is the car’s speed?




3. A rock is rolling down a hill with a velocity of 4.67m/s. It has a kinetic energy of 18,900J. What is the mass of the rock?



4. Calculate the kinetic energy of an airliner with a mass of 7,600kg that is flying at a speed of 147m/s.




plz help as this will help my grade

Respuesta :

samueladesida43

Answer:

1. 5480.31 J

2. 15.01 m/s

3. 1733.24 kg

4. 82,114,200 J

Explanation:

Kinetic energy is calculated thus;

K.E = ½ m × v2

Where;

m = mass (kg)

v = speed or velocity (m/s)

1. V = 11.9m/s, m = 77.4kg

K.E = ½ × 77.4 × 11.9²

K.E = ½ × 77.4 × 141.61

K.E = ½ × 10960.614

K.E = 5480.31 J

2. m = 654kg, K.E = 73,700J, v = ?

73700 = ½ × 654 × v²

73700 = 327v²

v² = 73700/327

v² = 225.38

v = √225.38

v = 15.01 m/s.

3. V = 4.67m/s, K.E = 18,900J, m = ?

18900 = ½ × m = 4.67²

18900 = ½ × m × 21.81

18900 = 10.9m

m = 18900/10.9

m = 1733.24 kg

4. K.E = ?, m = 7600kg, v = 147m/s

K.E = ½ × 7600 × 147²

K.E = 3800 × 21609

K.E = 82,114,200 J

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