He reorganized life into five kingdoms
If the angle is either 0 or 180, that means that there is either negative or positive work, so A and D are not correct.
If the angle is 45, then there is still some work involved.
The only option where there is no work done by a force is B. when the angle is between the force and displacement is 90.
Heat of combustion.<span> The calorific value is the total energy released as heat when a substance undergoes complete combustion with oxygen under standard conditions. The chemical reaction is typically a hydrocarbon or other organic molecule reacting with oxygen to form carbon dioxide and water and release heat.</span>
(1)
Cheetah speed: 
Its position at time t is given by
(1)
Gazelle speed: 
the gazelle starts S0=96.8 m ahead, therefore its position at time t is given by
(2)
The cheetah reaches the gazelle when 
. Therefore, equalizing (1) and (2) and solving for t, we find the time the cheetah needs to catch the gazelle:
(2) To solve the problem, we have to calculate the distance that the two animals can cover in t=7.5 s.
Cheetah: 
Gazelle: 
So, the gazelle should be ahead of the cheetah of at least
Answer:
C 2000v its obviously ans because if o is 1000 2 vo is 2000v
