I found an answer from en.wikipedia.org

Cheetah - Wikipedia

The cheetah (Acinonyx jubatus) is a large cat native to Africa and central Iran. It is the fastest land animal, estimated to be capable of running at 80 to 128 km/h (50 to 80 mph) with the fastest reliably recorded speeds being 93 and 98 km/h (58 and 61 mph), ... The cheetah typically stalks its prey to within 60–70 m (200–230 ft), charges ...

For more information, see Cheetah - Wikipedia

I found an answer from www.calculatorsoup.com

Kinetic Energy Calculator

In classical mechanics, kinetic energy (KE) is equal to half of an object's mass (1/ 2*m) multiplied by the velocity squared. For example, if a an object with a mass of  ...

For more information, see Kinetic Energy Calculator

Kinetic energy is the energy that an object has as a result of its motion.

K.E = \frac{1}{2} mv^2

Where, m - mass of an object and v - velocity of the object

Step 1: Calculating mass of the bear

Given that

Speed of the bear v = 12 m/s

Kinetic energy of the bear K.E = 32,000 joules

Mass of the bear m = ?

Get an expression for mass of the bear

K.E = \frac{1}{2} mv^2   

m = \frac{2K.E}{v^2}

Plugging the given values into the above equation

m = \frac{2*32,000}{(12)^2}

m = \frac{2*32,000}{(144}

m = 444.4

Hence, mass of the bear m = 444.4 kg