None of the choices is correct.
If two runners take the same amount of time to run a mile,
they have the same average speed. But their velocities
are not the same unless both runners begin and end their
run at the same points.
Speed is (distance covered) divided by (time to cover the distance).
Velocity is not. It's something different.
'Velocity' is not just a bigger word for 'speed'.
Answer:
Stress does not cause illness, but restrains the immune system's ability to fight foreign invaders
Explanation:
It's correct :)
Answer:
(A) She needs to move the decimal point by 3 places
The statement "Good locations for turbines are limited" describes a drawback to wind energy.
Answer: Option B
<u>Explanation:</u>
Wind energy is one of the most useful and efficient renewable energy sources. But nothing is ideal in this universe and the same thing applies for wind energy also. The generation of electricity from wind energy requires setting up of turbines.
And these turbines can be set up in plane areas which is free from any disturbance except wind flow. In open area and flat plane surface only the turbines can rotate freely with the effect of wind.
But regions where the wind flow is minimum due to snow formation like the northern region of earth, the turbines cannot be set up there. So the locations for setting up of turbines are limited for good outcome in wind energy. This is one of the drawback of wind energy.
Answer:
Force, F = 187.42 N
Explanation:
It is given that,
Mass of boy, m = 30 kg
Acceleration due to gravity, 
Radius of curvature of the roller coaster, r = 15 m
Speed of the car, v = 7.3 m/s
The force acting on the boy are force of gravity and the centripetal force. The net force acting on him is as follows :



F = 187.42 N
So, he press against the seat with a force is 187.42 N. Hence, this is the required solution.