The calculation for kinetic energy is this
KE = 1/2mv^2
KE = 1/2(50)(7^2)
KE = 1/2(49•50)
KE = 1225 kgm^2/s^2.
Or simply 1225 J.
She possess this much energy when she runs.
Answer:
10.6 s
Explanation:
Given that a girl is running the 200 m dash. She starts by acceleration at 8m/s^2 for 7s. Then continues at this speed until the end of the race. How long did it take for her to complete the race?
Solution.
If she accelerated for 7s, the velocity at which she accelerated will be:
Acceleration = velocity/time
8 = V/7
Make V the subject of the formula by cross multiplying.
V = 8 × 7
V = 56 m/s
She maintains the speed through out the journey.
Speed = distance/time
Make time the subject of formula
Time = distance/speed
Time = 200 / 56
Time = 3.57s
Therefore, she will complete the race by 7 + 3.6 = 10.6 s
Here a cat is running at constant speed which is given as 10 km/h for 5s
So here the average speed is defined as total distance moved in total time interval
so here it is given by

since
here speed of cat is constant so it will remain the same
And hence the average speed and instantaneous speed at any instant for this duration will remain the same
so here answer would be
<em>average speed = 10 km/h</em>
<em>instantaneous speed = 10 km/h</em>