Two girls each weight 500 N. Ride in a car traveling at 20.0 m/s. One wears a seat belt. The other does not. In an accident the girl wearing the seat belt is brought to a stop in 0.120 seconds. The dashboard brings the other one to a stop in only 0.00800 seconds.
What is the impulse exerted on each girl?
What is the force exerted on each girl?
force*time=impulse*mass*changevelocity
Two girls each weight 500 N. Ride in a car traveling at 20.0 m/s. One wears a seat belt. The other does not. In an accident the girl wearing the seat belt is brought to a stop in 0.120 seconds. The dashboard brings the other one to a stop in only 0.00800 seconds.
What is the impulse exerted on each girl?
What is the force exerted on each girl?
physics - bobpursley, Thursday, February 3, 2011 at 6:36pm
force*time=impulse*mass*changevelocity
please explain. I don't understand
To find the impulse exerted on each girl, we can use the equation:
Impulse = Change in momentum
The momentum of an object can be calculated using the formula:
Momentum = Mass * Velocity
1. Impulse exerted on the girl wearing the seat belt:
Since the girl wearing the seat belt is brought to a stop, her final velocity is 0 m/s. The initial velocity is given as 20.0 m/s. We can calculate her momentum before the accident as:
Momentum = Mass * Velocity
Momentum = 500 N * 20.0 m/s
Momentum = 10,000 Ns
Since her final velocity is 0, her change in momentum is:
Change in momentum = Final momentum - Initial momentum
Change in momentum = 0 Ns - 10,000 Ns
Change in momentum = -10,000 Ns
Therefore, the impulse exerted on the girl wearing the seat belt is -10,000 Ns.
2. Impulse exerted on the other girl:
Similarly, we can calculate the momentum of the girl who does not wear a seat belt. Her final velocity is also 0 m/s, but her initial velocity is still 20.0 m/s. Thus, her momentum before the accident is:
Momentum = Mass * Velocity
Momentum = 500 N * 20.0 m/s
Momentum = 10,000 Ns
Her change in momentum is:
Change in momentum = Final momentum - Initial momentum
Change in momentum = 0 Ns - 10,000 Ns
Change in momentum = -10,000 Ns
Therefore, the impulse exerted on the girl not wearing a seat belt is also -10,000 Ns.
To find the force exerted on each girl, we can use the formula:
Force = Impulse / Time
3. Force exerted on the girl wearing the seat belt:
The impulse exerted on the girl wearing the seat belt is -10,000 Ns, and the time taken to stop is 0.120 seconds. We can calculate her force as:
Force = (-10,000 Ns) / (0.120 s)
Force = -83,333.33 N
Since force is a vector quantity, the negative sign indicates that the force is directed opposite to the motion.
4. Force exerted on the other girl:
The impulse exerted on the other girl is also -10,000 Ns, but her stopping time is given as 0.00800 seconds. We can calculate her force as:
Force = (-10,000 Ns) / (0.00800 s)
Force = -1,250,000 N
Again, the negative sign indicates that the force is directed opposite to the motion.
Therefore, the impulse exerted on each girl is -10,000 Ns, and the force exerted on the girl wearing the seat belt is approximately -83,333.33 N while the force exerted on the other girl is approximately -1,250,000 N.