A 1100kg car starts from rest, accelerates for 5 seconds. The magnitude of acceleration is (a)= 4.6m/s2. find the average power generated by the net force that accelerates the vehicle? what do i do here
i know that F=ma= 1100x4.6=5060=F and
Wnet = 1/2mvf2-1/2mvi2 since it starts from rest Vi= 0
so 1/2mvf2 =(1/2)(1100)(4.6?)=11638 im a doing this right if not can someone tell me what to do?
No.
What is the final velocity?
vf= at= 4.6*5 m/s
What is the KE gained?
1/2 m vf^2 (no initial KE)
Work it took to provide this KE is equal to the KE.
Power= work/time= KE/time
VF=23m/s
KE=290,950
Power=58,190
is this correct?
thanx natali
To find the average power generated by the net force that accelerates the vehicle, you can use the equation:
Power = Work / Time
Here's how you can calculate it step-by-step:
1. Find the final velocity of the car using the given acceleration and time:
vf = vi + at
Since the car starts from rest (vi = 0), vf = 0 + (4.6 m/s^2) × 5 s
vf = 23 m/s
2. Calculate the work done on the car by the net force:
Work = ΔKE (change in kinetic energy)
Since the car starts from rest, its initial kinetic energy (KEi) is zero.
The final kinetic energy (KEf) can be calculated using the formula: KEf = 1/2 mvf^2
KEf = (1/2) × (1100 kg) × (23 m/s)^2
3. Substitute the calculated values back into the power equation to find the average power:
Power = Work / Time
Power = KEf / t
Power = [(1/2) × (1100 kg) × (23 m/s)^2] / 5 s
Calculating this expression will give you the average power generated by the net force that accelerates the vehicle.
To find the average power generated by the net force that accelerates the vehicle, you need to calculate the work done and divide it by the time taken.
First, calculate the work done using the formula:
Work (W) = Force (F) × Distance (d).
In this case, the distance the car travels can be found using the formula for uniform acceleration:
Distance (d) = Initial velocity (Vi) × Time (t) + (1/2) × Acceleration (a) × Time squared (t^2).
Since the car starts from rest, the initial velocity (Vi) is 0. Therefore:
Distance (d) = (1/2) × Acceleration (a) × Time squared (t^2).
Distance (d) = (1/2) × 4.6 m/s^2 × (5 s)^2 = 57.5 meters.
Now, substitute the force (F) and distance (d) values into the equation for work:
Work (W) = Force (F) × Distance (d).
Work (W) = 5060 N × 57.5 m = 290300 J (joules).
Finally, divide the work done by the time taken to find the average power:
Average Power = Work (W) / Time (t).
Average Power = 290300 J / 5 s = 58060 watts or 58.06 kilowatts.