A green 4 kg toy car with a speed of 5 m/s collides head-on with a stationary yellow 1-kg car. After the collision, the cars are locked together with a speed of 4 m/s. How much kinetic energy is lost in the collision?
a. what is the kinetic energy of the green 4-kg toy care BEFORE the collision?
b. What is the kinetic energy of the yellow 1-kg toy care BEFORE the collision.
c. What is the kinetic energy of the two cars after the collision?
To calculate the kinetic energy (KE) of an object, we use the formula KE = (1/2)mv^2, where m is the mass of the object and v is its velocity.
a. To find the kinetic energy of the green 4-kg toy car before the collision, we can use the formula KE = (1/2)mv^2, where m = 4 kg and v = 5 m/s. Plugging in the values, we get KE = (1/2)(4 kg)(5 m/s)^2 = 50 J.
b. Similarly, to find the kinetic energy of the yellow 1-kg toy car before the collision, we can use the same formula KE = (1/2)mv^2, where m = 1 kg and v = 0 m/s (since it is stationary). Plugging in the values, we get KE = (1/2)(1 kg)(0 m/s)^2 = 0 J, as the kinetic energy of an object at rest is zero.
c. After the collision, the cars are locked together, so we need to calculate the combined kinetic energy of the two cars. To find this, we can add up the kinetic energy of the individual cars. Since they are moving with a speed of 4 m/s together, we need to find the combined mass.
The combined mass can be calculated by adding the individual masses, so in this case, it will be 4 kg (green car) + 1 kg (yellow car) = 5 kg.
Using the formula KE = (1/2)mv^2 again, where m = 5 kg and v = 4 m/s, we get KE = (1/2)(5 kg)(4 m/s)^2 = 40 J.
Therefore, the kinetic energy lost in the collision can be found by subtracting the final kinetic energy (40 J) from the initial kinetic energy (50 J): 50 J - 40 J = 10 J. So, 10 Joules of energy are lost in the collision.