Questions: A 2 kg skateboard is rolling across a smooth, flat floor when a girl kicks it, causing it to speed up to 4.5 m / s in 0.5 seconds without changing direction. If the average force exerted by the girl on the skateboard in its direction of motion was 6 N, with what initial velocity was it moving?
Transcript text: 8. A 2 kg skateboard is rolling across a smooth, flat floor when a girl kicks it, causing it to speed up to $4.5 \mathrm{~m} / \mathrm{s}$ in 0.5 seconds without changing direction. If the average force exerted by the girl on the skateboard in its direction of motion was 6 N , with what initial velocity was it moving?
Solution
Solution Steps
Step 1: Understand the Problem
We need to find the initial velocity of the skateboard. We know the final velocity, the time over which the force was applied, and the average force exerted. We can use the principles of physics, specifically Newton's second law and the equations of motion, to solve this problem.
Step 2: Use Newton's Second Law
Newton's second law states that the force exerted on an object is equal to the mass of the object multiplied by its acceleration: