I have multiple questions like the following and need help on how to work out the answer of one because our book does not cover impulse.
a car is at rest when it experiences a fwd propulsion force to set it in motion. it then experiences a second fwd propulsion force to speed it up more. finally it brakes to a stop.
I=
(change in )P=
Fapp=4000N
at rest P1=0
t=4.0s
P2=
I=
(change in P)=
Fapp=6000N
t=3.0s
P3=
I=
(change in) P=
Ffrict=8000N
t=
Stopped
P4= (I am assuming 0)
To solve these questions, we need to use the concept of impulse. Impulse is defined as the change in momentum, and it can be calculated using the formula:
Impulse = Change in momentum (ΔP) = Force (F) × time (Δt)
To find the change in momentum (ΔP), we need to know the initial momentum (P1), the force applied (F), and the time interval (Δt). Please note that momentum (P) is a vector, so it has both magnitude and direction.
Let's walk through the process of solving the first question step by step:
Question 1:
A car is at rest when it experiences a forward propulsion force to set it in motion. It then experiences a second forward propulsion force to speed it up more. Finally, it brakes to a stop.
Initial momentum (P1) = 0 (since the car is initially at rest)
Applied force (Fapp) = 4000N
Time interval (Δt) = 4.0s
Final momentum (P2) = ?
To find the final momentum (P2), we'll use the impulse formula:
Impulse = ΔP = F × Δt
Substituting the given values:
ΔP = 4000N × 4.0s
Now, let's calculate the impulse:
ΔP = 16000 N·s
Therefore, the change in momentum (ΔP) is 16000 N·s. Since the initial momentum (P1) is 0, the final momentum (P2) will also be 16000 N·s.
Thus, the answer to the first question is:
P2 = 16000 N·s
You can follow this same process to solve the remaining questions by substituting the given values of force (F) and time interval (Δt) into the impulse formula and calculating the impulse (ΔP). If the car is stopped, as mentioned in the last question, the change in momentum (ΔP) will be 0.
I hope this explanation helps you solve the questions. Let me know if there's anything else I can assist you with!