The parachute on a race car of weight 8850 N opens at the end of a quarter-mile run when the car is traveling at 31 m/s. What total retarding force must be supplied by the parachute to stop the car in a distance of 1000 m?
[so for this one, i need to know the mass and acceleration. i used the at+v0 =v equation and the distance=.5at^2+v0t equation to solve for t which i got as 64.5 seconds. and then I plugged that into the at+v0 =v to get acceleration of -.4805=a anddd now i don't know what to do. please let me know if the prev. steps were correct!] thank you
subject = physics
Vf^2=Vi^2 -2ad but a=force/mass
Vf=0 Vi=31 solve for force
Yes, your previous steps were correct! Now that you have found the acceleration of the car, you can use that along with the weight of the car to calculate the total retarding force needed to stop the car.
To do this, we can use Newton's second law of motion, which states that the force acting on an object is equal to its mass multiplied by its acceleration. In this case, the force we are looking for is the retarding force provided by the parachute.
First, let's find the mass of the car using the weight equation: weight = mass * gravity. Rearranging the equation, we have mass = weight / gravity.
Given that the weight of the car is 8850 N, and assuming the acceleration due to gravity is 9.8 m/s^2, we can calculate the mass of the car as follows:
mass = 8850 N / 9.8 m/s^2 = 902.04 kg
Now that we know the mass of the car, we can use Newton's second law to calculate the total retarding force required to stop the car. The equation is:
force = mass * acceleration
Substituting the values we have:
force = 902.04 kg * (-0.4805 m/s^2) = -433.57 N
The negative sign indicates that the force is in the opposite direction to the motion of the car (as it's retarding force). So, the total retarding force required by the parachute to stop the car in a distance of 1000 m is approximately 433.57 N.