Answer:
3. 9600m/s
4. 2.5m/s
Step-by-step explanation:
To find the final velocity of the object which accelerates at 40m/s/s for four minutes, we first need to convert the 4 minutes to seconds. There are 60 seconds in a minute so 4 minutes is equal to 4x60 = 240 seconds.
To calculate the final velocity we just multiply the acceleration rate by the time, so 40x240=9,600 m/s
The final velocity of the object would be 9600m/s.
If an object's final velocity was 115m/s after 45 seconds then we need to find out how much it accelerated in that 45 seconds to find the starting velocity. 45x2.5=112.5 It increased in speed by 112.5m/s over 45 seconds, so its initial speed was 112.5m/s slower than its final speed. 115-112.5=2.5, the object's starting velocity was 2.5m/s.
Hope this helped!