Question

1. A cheetah can run at a top velocity of 31 m/s and has a mass of 47 kg. What is the cheetahs kenetic energy?

2. A leatherback turtle, although slow on land, is fast in the water, with a top velocity of 9.78 m/s. With a kinetic energy of 60,800 j, what is its mass?

3. The kinetic energy of a gold ball was measured at 143.3 joules and has a mass of .047 kg what is its speed?

Answer 1

1. 22583.5 J

2. 1248 kg

3. 78.09 m/s

Explanation:

The formula for kinetic energy is ;

K.E = 1/2* m * v²

Where m is the mass and v is the velocity

1.

K.E = 1/2 * m*v²

K.E = 1/2 * 47 * 31²

K.E = 22583.5 J

2.

Velocity = 9.78 m/s.

Kinetic energy = 60,800 J

To get mass, apply the formula as;

K.E = 1/2 * m*v²

60,800 = 1/2 * m * 9.78²

60800 = 48.70845 m

60800/48.70845 = m

1248 = m

Mass = 1248 kg

3.

K.E = 143.3 J

Mass = 0.047 kg

Apply the formula;

K.E = 1/2 * m*v²

143.3 = 1/2 * 0.047 * v²

143.3 = 0.0235 v²

143.3/0.0235 = v²

6097.87 = v²

v = √6097.87

v= 78.09 m/s