A car has a kinetic energy of 1.9 × 103 joules. If the velocity of the car is decreased by half, what is its kinetic energy? 2.2 × 102 joules 4.7 × 102 joules 5.2 × 102 joules 5.8 × 103 joules
If the velocity is decreased by half, then Kinetic energy will reduced to it's 4 times,
= 1.9 10³ / 4
= 4.75 10²
In short, Your Answer would be Option B
Hope this helps!
Answer:
4.7 x 10^2 Joule
Explanation:
The energy possessed by the motion of body is called its kinetic energy.
The formula for the kinetic energy of a body is given by
K.E = \frac{1}{2}mv^{2}
The kinetic energy is directly proportional to the square of velocity and the mass of body.
\(K_{1} = \frac{1}{2}mv^{2}\) ..... (1)
\(K_{2} = \frac{1}{2}m\left ( \frac{v}{2} \right )^{2}\) ..... (2)
Dividing equation ((2) by equation (1), we get
\(K_{2} = \frac{K_{1}}{4}\)
\(K_{2} = \frac{1.9 \times 10^{3}}{4}\)
K2 = 4.7 x 10^2 Joule