a truck goes from a stop to 60 km/hr brakes for a light and stops in a 8 seconds what is the rate of deceleration?
the speed decreased, so
a = -60km/hr / 8s = -15/2 km/hr/s
That is, every second the speed decreased by 15/2 km/hr
To find the rate of deceleration, we need to use the equation:
acceleration = (final velocity - initial velocity) / time
Given:
Initial velocity (u) = 60 km/hr
Final velocity (v) = 0 km/hr
Time (t) = 8 seconds
Now, let's convert the velocities from km/hr to m/s, as the SI unit for acceleration is m/s^2:
Initial velocity (u) = 60 km/hr = 60 * (1000/3600) m/s = 16.67 m/s
Final velocity (v) = 0 km/hr = 0 m/s
Substituting the values into the formula:
acceleration = (v - u) / t
acceleration = (0 - 16.67) / 8
acceleration = -16.67 / 8
acceleration ≈ -2.084 m/s^2
Therefore, the rate of deceleration is approximately -2.084 m/s^2. The negative sign indicates deceleration (as opposed to acceleration).
To find the rate of deceleration, you need to know the change in velocity and the time taken for that change to occur.
Here's how you can calculate it step by step:
Step 1: Convert the initial velocity from km/hr to m/s.
Given initial velocity = 0 km/hr (since the truck starts from a stop)
Converting from km/hr to m/s:
0 km/hr ÷ 3.6 = 0 m/s (since 1 km/hr = 1 m/s ÷ 3.6)
Step 2: Convert the final velocity from km/hr to m/s.
Given final velocity = 60 km/hr
Converting from km/hr to m/s:
60 km/hr ÷ 3.6 = 16.67 m/s (rounded to two decimal places)
Step 3: Calculate the change in velocity.
Change in velocity = Final velocity - Initial velocity
Change in velocity = 16.67 m/s - 0 m/s = 16.67 m/s
Step 4: Calculate the rate of deceleration (acceleration in negative direction).
Rate of deceleration = Change in velocity ÷ Time taken
Time taken = 8 seconds
Rate of deceleration = 16.67 m/s ÷ 8 s = 2.08 m/s² (rounded to two decimal places)
Therefore, the rate of deceleration for the truck is approximately 2.08 m/s².