I believe the percentage is between 15-20%. Stress is a well known factor that affects the performance of people.
Answer:
s=800 m
Explanation:
Given that,
Acceleration of a runner, a = 4 m/s²
Time, t = 20 seconds
We need to find the distance covered by her. Initially, she was at rest. It means its initial velocity is equal to 0. So, using second equation of motion as follows :

Herre, u = 0

So, she will cover a distance of 800 m.
Answer:
c) may also be conserved
Explanation:
Momentum is conserved in both elastic and inelastic type of collisions.
But the differences is that:
In an ELASTIC type of collisions, KINETIC ENERGY IS ALSO CONSERVED.
whereas, In an INELASTIC type of collision, KINETIC ENERGY IS NOT CONSERVED.
So unless until type of collision is specified, we can not say anything about the conservation of kinetic energy after collision.
Hence, may also be conserved is the appropriate option here.