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2 years ago

10

The potential energy of a catapult was completely converted into kinetic energy by releasing a small stone with a mass of 20 gra

ms. The velocity of the stone when it reached the target was 15.0 meters/second. What was the value of the kinetic energy of the stone when it reached the target? A. 2.05 joules B. 2.25 joules C. 3.20 joules D. 4.43 joules

2 answers:

Blababa [14]2 years ago

4 0

Answer : The correct option is, 2.25 joules.

Explanation : Given,

Mass of the stone = 20 g

Velocity of the stone = 15 m/s

Formula used for kinetic energy is :

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

where,

K.E = kinetic energy of the stone

m = mass of the stone

v = velocity of the stone

Now put all the given values in this formula, we get the kinetic energy of the stone.

$K.E=\frac{1}{2}\times (20g)\times (15m/s)^2$

$K.E=2250gm^2/s^2=2.25Kgm^2/s^2=2.25J$

Therefore, The kinetic energy of the stone is, 2.25 joules.

vladimir1956 [14]2 years ago

3 0

1,000 grams = 1 kilogram

20 grams = 0.02 kilogram

Kinetic energy = (1/2) (mass) x (speed)²

(1/2) (0.02) x (15)² =

(0.01) x (225) = 2.25 joules

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