a child is sliding on a sled at 1.5m/s to the right. You stop the sled by pushing on it for 0.50 s in a direction opposite to its motion. If the mass of the child and the sled is 35kg. what average force do need to apply to stop the sled. Use the concepts of impulse and motion
force*time= mass*changeinvelocity
Every single the I attempt solving this problem and every different equation I use and could ever think of using I get an answer of -105 N and yet for some reason beyond my comprehension the book gives an answer of -110N
you're not following the sig fig rule- it's -110 because you can only have 2 significant figures.
Zero isn't a significant number. Only if it was between the ones would it be considered a significant number.
To find the average force required to stop the sled, we can use the concept of impulse and motion. The impulse experienced by an object is defined as the product of the force acting on it and the time interval during which the force is applied. Mathematically, impulse (J) is given by the equation:
J = F * Δt
Where:
J is the impulse
F is the force applied on the object
Δt is the time interval during which the force is applied
In this case, the sled is initially moving to the right with a velocity of 1.5 m/s. To stop the sled, we need to apply a force in the opposite direction of its motion.
Given:
Initial velocity (u) = 1.5 m/s (to the right)
Final velocity (v) = 0 m/s (since the sled is stopped)
Mass of the sled (m) = 35 kg
Time interval (Δt) = 0.50 s
To determine the impulse exerted on the sled, we can use the equation:
J = m * (v - u)
Substituting the values:
J = 35 kg * (0 m/s - 1.5 m/s)
J = -52.5 kg·m/s
The negative sign indicates that the force applied is in the opposite direction of the sled's motion. Since we want to find the average force (F), we can divide the impulse by the time interval:
F = J / Δt
Substituting the values:
F = -52.5 kg·m/s / 0.50 s
F = -105 N
Therefore, the average force required to stop the sled is 105 Newtons, directed opposite to its motion.