Joanne drives her car with a mass of 1000 {\rm kg} at a speed of 23m/s .
Find a road friction force that is need to bring her car to a halt in 14s .
V = Vo + a*t.
a = (V-Vo)/t = (0-23)/14 = -1.64 m/s^2.
F = m*a = 1000*(-1.64) = -1640 N.
The negative sign means that the force
is opposing vehicle movement.
Well, Joanne should probably use the brakes and not rely on her charm to bring her car to a halt. But let's calculate the road friction force required to stop the car.
To find the friction force, let's first find the car's initial velocity, final velocity, and the time it takes to stop.
Given:
Mass of the car, m = 1000 kg
Initial velocity, v₁ = 23 m/s
Time, t = 14 s
Now, to find the final velocity, we can use the equation: v₂ = v₁ + at.
We want the final velocity to be 0 m/s (since the car needs to come to a halt), so the equation becomes:
0 = 23 m/s + a(14 s).
Now, let's solve for the acceleration, a:
a = -23 m/s / 14 s
a ≈ -1.64 m/s²
The negative sign indicates that the car is decelerating (slowing down).
Now, to find the friction force, we can use Newton's second law, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration:
Friction force, F = mass × acceleration
F = 1000 kg × -1.64 m/s²
And the friction force is approximately -1640 N (newtons).
So, Joanne needs a road friction force of -1640 N to bring her car to a halt. But hey, let's hope she doesn't need that much force to stop. Safe travels!
To find the road friction force needed to bring the car to a halt, we can use Newton's second law of motion, which states that the net force acting on an object is equal to the product of its mass and acceleration.
First, let's calculate the acceleration of the car using the given information. The car is initially moving at a speed of 23 m/s and comes to a stop in 14 s.
Acceleration = Change in Velocity / Time
Acceleration = (Final Velocity - Initial Velocity) / Time
Acceleration = (0 - 23 m/s) / 14 s
Acceleration = -23 m/s / 14 s
Now, let's calculate the acceleration:
Acceleration = -1.64 m/s^2
Since the car is coming to a halt, the acceleration is negative.
Now, we can calculate the road friction force needed using Newton's second law:
Net Force = Mass * Acceleration
Net Force = 1000 kg * (-1.64 m/s^2)
Net Force = -1640 N
Therefore, the road friction force needed to bring the car to a halt is 1640 N in the opposite direction of the car's motion.
To find the road friction force needed to bring Joanne's car to a halt, we can use Newton's second law of motion, which states that the net force acting on an object is equal to the product of its mass and acceleration.
First, let's calculate the acceleration of the car using the formula:
acceleration = (final velocity - initial velocity) / time
Given that the initial velocity (u) is 23 m/s, the final velocity (v) is 0 (since the car comes to a halt), and the time (t) is 14 s, we can substitute these values into the formula:
acceleration = (0 - 23) / 14
Now, let's calculate the acceleration:
acceleration = -23 / 14
Next, we can use Newton's second law of motion to find the road friction force:
force = mass × acceleration
Given that the mass (m) of the car is 1000 kg, we can substitute these values into the formula:
force = 1000 kg × (-23 / 14)
Now, let's calculate the road friction force:
force = -23000 / 14
Simplifying the expression, we have:
force ≈ -1642.86 N
Therefore, the road friction force needed to bring Joanne's car to a halt is approximately 1642.86 Newtons. Note that the negative sign indicates that the force is acting in the opposite direction to the car's motion, thus causing it to come to a halt.