Answer:
B.The force of friction between the block and surface will decrease.
Explanation:
The force of friction is given by
where is the coefficient of friction and is the normal force.
When the student pulls on the block with force at an angle , the normal force on the block becomes
and hence the frictional force becomes
.
Now, as we increase , increases which as a result decreases the normal force , which also means the frictional force decreases; Hence choice B stands true.
<em>P.S: Choice D is tempting but incorrect since the weight </em><em> is independent of the external forces on the block. </em>
Answer:
The apple
Explanation:
The apple has gravitational potential energy because it is just sitting there but nothing is pushing it up, it is not sitting on something. This means that it has a lot of gravitational potential energy as nothing is pushing it up.
Answer:
Explanation:
Take at look to the picture I attached you, using Kirchhoff's current law we get:
This is a separable first order differential equation, let's solve it step by step:
Express the equation this way:
integrate both sides, the left side will be integrated from an initial voltage v to a final voltage V, and the right side from an initial time 0 to a final time t:
Evaluating the integrals:
natural logarithm to both sides in order to isolate V:
Where the term RC is called time constant and is given by:
The equation (option 3) represents the horizontal momentum of a 15 kg lab cart moving with a constant velocity, v, and that continues moving after a 2 kg object is dropped into it.
The horizontal momentum is given by:
Where:
- m₁: is the mass of the lab cart = 15 kg
- m₂: is the <em>mass </em>of the object dropped = 2 kg
- : is the initial velocity of the<em> lab cart </em>
- : is the <em>initial velocit</em>y of the <em>object </em>= 0 (it is dropped)
- : is the final velocity of the<em> lab cart </em>
- : is the <em>final velocity</em> of the <em>object </em>
Then, the horizontal momentum is:
When the object is dropped into the lab cart, the final velocity of the lab cart and the object <u>will be the same</u>, so:
Therefore, the equation represents the horizontal momentum (option 3).
Learn more about linear momentum here:
I hope it helps you!
D. a foot model
btw this is a joke right cuz there ain’t no picture lol