I made the drawing in the attached file.
I included two figures.
The upper figure shows the effect of:
- multiplying vector A times 1.5.
It is drawn in red with dotted line.
- multiplying vector B times - 3 .
It is drawn in purple with dotted line.
In the lower figure you have the resultant vector: C = 1.5A - 3B.
The method is that you translate the tail of the vector -3B unitl the point of the vector 1,5A, preserving the angles.
Then you draw the arrow that joins the tail of 1,5A with the point of -3B after translation.
The resultant arrow is the vector C and it is drawn in black dotted line.
Good work on solving part a).
b) may look complicated, but it's not too bad.
It says that the body is 25% efficient in converting fat to mechanical energy.
In other words, only 25% of the energy we get from our stored fat shows up
in the physical, mechanical moving around that we do. (The rest becomes
heat, which dissipates into the environment as we keep our bodies warm,
breathe hot air out,and perspire.)
You already know how much mechanical energy the climber needed to lift
himself to the top of the mountain... 2.4x10⁶ joules.
That's 25% of what he needs to convert in order to accomplish the climb.
He needs to pull 4 times as much energy out of fat.
-- Fat energy required = 4 x (2.4 x 10⁶) = 9.6 x 10⁶ joules.
-- Amount stored in 1kg of fat = 3.8 x 10⁷ joules
-- Portion of a kilogram he needs to use = (9.6 x 10⁶) / (3.8 x 10⁷)
Note:
That much of a kilogram weighs about 8.9 ounces ... which shows why it's so
hard to lose weight with physical exercise alone. It also helps you appreciate
that fat is much more efficient at storing energy than batteries are ... that one
kilogram of fat stores the amount of energy used by a 100-watt light bulb, to
burn for 105 hours (more than 4-1/2 days ! ! !)
Answer:
Explanation:
The strength of an electric field E produced by a single charge Q at a distance d from it is given by the formula: , where K represents the Coulomb constant.
Since the electric field E is derived from the Coulomb Force per unit charge using a positive test charge, the field's units will be in units of Newtons/Coulomb, and be the formula for the Coulomb electric force between to charges (Q1 and Q2),
but modified with only one charge showing in the numerator of the expression.
The minimum input force she'll need to lift the ball is 35 N.
Explanation:
Mechanical advantage of a single pulley is 1. As, she applies 70 N of force to lift the bowling ball, so the output force(weight of the ball) is also 70 N.
Now, adding another pulley gives a mechanical advantage of 2. We have,
M.A = (Output Force)/(Input Force)
Substituting the values we get,
= 35 N
Input force equals to 35 N needs to be applied.
Answer:
Explanation:
i = Imax sin2πft
given i = 180 , Imax = 200 , f = 50 , t = ?
Put the give values in the equation above
180 = 200 sin 2πft
sin 2πft = .9
sin2π x 50t = .9
sin 360 x 50 t = sin ( 360n + 64 )
360 x 50 t = 360n + 64
360 x 50 t = 64 , ( putting n = 0 for least value of t )
18000 t = 64
t = 3.55 ms .
