Over a time interval of 1.98 years, the velocity of a planet orbiting a distant star reverses direction, changing from +21.9 km/s to -17.2 km/s. Find (a) the total change in the planet's velocity (in m/s) and (b) its average acceleration (in m/s2) during this interval. Include the correct algebraic sign with your answers to convey the directions of the velocity and the acceleration.
Please help!
Or options r
Ms susie -- I doubt if you know anything about physics. Please do not answer any questions unless you are absolutely sure you are right.
I did one like that recently
https://www.jiskha.com/display.cgi?id=1517378428
To find the total change in velocity, you need to find the difference between the final velocity and the initial velocity. The total change in velocity can be calculated by subtracting the initial velocity from the final velocity.
(a) Total change in velocity:
Final velocity = -17.2 km/s
Initial velocity = +21.9 km/s
To ensure consistent units, convert both velocities to m/s:
1 km = 1000 m
Final velocity (in m/s) = -17.2 km/s * (1000 m/1 km) = -17,200 m/s
Initial velocity (in m/s) = +21.9 km/s * (1000 m/1 km) = +21,900 m/s
Now, calculate the total change in velocity:
Total change in velocity = Final velocity - Initial velocity
Total change in velocity = -17,200 m/s - (+21,900 m/s)
Total change in velocity = -17,200 m/s - 21,900 m/s
Total change in velocity = -39,100 m/s
The total change in velocity is -39,100 m/s (Note the negative sign, which indicates the direction of the change).
(b) To find the average acceleration, you need to calculate the change in velocity per unit of time. Since the time interval is provided as 1.98 years, you first need to convert it to seconds.
1 year = 365.25 days (considering the leap year)
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
Total time in seconds:
1.98 years * 365.25 days/year * 24 hours/day * 60 minutes/hour * 60 seconds/minute = 62,298,480 seconds
Average acceleration (in m/s^2) = Total change in velocity / Total time interval
Average acceleration (in m/s^2) = (-39,100 m/s) / (62,298,480 seconds)
Now, evaluate the average acceleration:
Average acceleration (in m/s^2) ≈ -0.627 m/s^2
The average acceleration is approximately -0.627 m/s^2. (Again, note the negative sign indicating the direction of acceleration)