A toy car with a mass of 120 g moves to the right with a speed of 0.56 m/s. A small child drops a 25.0-g piece of clay onto the car. The clay sticks to the car and the car continues to the right. What is the change in speed of the car? Consider the frictional force between the car and the ground to be negligible. Answer in m/s.
To solve this problem I tried to use m1v1=m2v2.
I plugged in 120(0.56) = (120+25)v2 = 120(0.56)=145v2 = 0.46 = v2
Then I tried to solve for the change in speed by taking v1-v2 = 0.56-0.46 = 0.1m/s.
This answer is wrong. Please assist.
1 answer
The unit of mass should always be kg. So, in this problem you shouldn't use 120 g and 25 g directly in the equation. Convert them!