a car starts from rest , attains a velocity of 36kmph with an acceleration of 0.2m/s^2 travels 9km with this uniform velocity and then comes to halt with a uniform acceleration of 0.1m/s^2 find the total time of travel of the car.
v = 36 km/hr =36000/3600 = 10 m/s.
1. v =a1•t1, t1= v/a = 10/0.2 = 50 s.
2. t2 = s/v = 9000/10 = 900 s.
3. 0 = v-a•t3,
t3 = v/a2 = 10/0.1 = 100 s.
t(total) = 50+900+100 = 1050 s = 17.5 min.
What is in the 2 nd step...im not getting it.
An automobile starts from rest and attains a velocity of 36km/hr in 30 minute .what is the acceleration in m/s2?
Seience slop
To find the total time of travel of the car, we need to calculate the time it takes for the car to accelerate to 36 km/h, the time it takes to travel 9 km with uniform velocity, and the time it takes to decelerate and come to a halt.
Let's break down the problem step by step:
Step 1: Finding the time to reach a velocity of 36 km/h
We know that the acceleration of the car is 0.2 m/s^2 and the initial velocity is 0 (rest). We need to convert the final velocity from km/h to m/s:
Final velocity = 36 km/h = 36 * (1000/3600) m/s = 10 m/s
We can use the following equation to calculate the time it takes to reach the final velocity:
Final velocity = Initial velocity + (Acceleration * Time)
Rearranging the equation:
Time = (Final velocity - Initial velocity) / Acceleration
Time = (10 - 0) / 0.2 = 50 seconds
So, it takes 50 seconds for the car to reach a velocity of 36 km/h.
Step 2: Finding the time to travel 9 km with uniform velocity
Since the car travels at a uniform velocity of 36 km/h, we can calculate the time it takes using the formula:
Time = Distance / Velocity
Distance = 9 km = 9 * 1000 m = 9000 m
Velocity = 36 km/h = 36 * (1000/3600) m/s = 10 m/s
Time = 9000 m / 10 m/s = 900 seconds
So, it takes 900 seconds to travel 9 km with uniform velocity.
Step 3: Finding the time to come to a halt with uniform deceleration
We know that the acceleration while coming to a halt is -0.1 m/s^2 (negative since it's deceleration). We need to calculate the time using the same equation as step 1:
Time = (Final velocity - Initial velocity) / Acceleration
Final velocity = 0 (comes to a halt)
Acceleration = -0.1 m/s^2
Initial velocity = 10 m/s (the uniform velocity from step 2)
Time = (0 - 10) / (-0.1) = 100 seconds
So, it takes 100 seconds for the car to come to a halt.
Step 4: Finding the total time of travel
The total time of travel is the sum of the times from step 1, step 2, and step 3:
Total time = Time to reach a velocity of 36 km/h + Time to travel 9 km with uniform velocity + Time to come to a halt
Total time = 50 seconds + 900 seconds + 100 seconds = 1050 seconds
Therefore, the total time of travel for the car is 1050 seconds.