Solution :
A vector is defined as an element that has magnitude of some measure and direction.
It is given there is vector 'd' which has magnitude 2.6 m and its direction is towards north.
a). -d
The magnitude of the vector '-d' is 2.6 m and its direction is reversed, i.e. its direction is towards south.
b). d/2.0
The magnitude of the vector 'd/2.0' is 1.3 m and its direction is towards north.
c). - 2.5d
The magnitude of the vector increases by 2.5 times i.e. 2.5 x 2.6 = 6.5 m and the direction is towards south.
d). 5.0d
The magnitude of the vector increases by 5 times i.e. 5 x 2.6 = 13 m and the direction is towards north.
Explanation:
In the picture.
I hope that it's a clear solution.
The question is incomplete. The complete question is :
Assume that the energy lost was entirely due to friction and that the total length of the PVC pipe is 1 meter. Use this length to compute the average force of friction (for this calculation, you may neglect uncertainties).
Mass of the ball : 16.3 g
Predicted range : 0.3503 m
Actual range : 1.09 m
Solution :
Given that :
The predicted range is 0.3503 m
Time of the fall is :

...........(i)
...........(ii)
Dividing the equation (ii) by (i)

∴ 
Now loss of energy = change in the kinetic energy
![$W=\frac{1}{2} m [v_0^2-v_1^2]$](https://tex.z-dn.net/?f=%24W%3D%5Cfrac%7B1%7D%7B2%7D%20m%20%5Bv_0%5E2-v_1%5E2%5D%24)
![$W=\frac{1}{2} \times (16.3 \times 10^{-3}) \times [v_0^2-\left(\frac{v_0}{3.11}\right)^2]$](https://tex.z-dn.net/?f=%24W%3D%5Cfrac%7B1%7D%7B2%7D%20%5Ctimes%20%2816.3%20%5Ctimes%2010%5E%7B-3%7D%29%20%5Ctimes%20%5Bv_0%5E2-%5Cleft%28%5Cfrac%7Bv_0%7D%7B3.11%7D%5Cright%29%5E2%5D%24)

If f is average friction force, then
(f)(L) = W
(f) (1) = 
(f) = 
Answer:
b. Research projects for a specific cause
Explanation:
Research funded by private foundations are usually for a specific cause. These type of research are usually properly scrutinized, and must have a high probability of success. Most of these projects may not be to benefit the consumers, but are usually done with a special purpose in mind.