(a) The block has a weight of (27.0 kg) <em>g</em>, and the normal force of the surface pushing upward on the block has the same magnitude, so that static friction exerts a maximum force of
<em>µ</em> (27.0 kg) <em>g</em> = 70.0 N
where <em>µ</em> is the coefficient of <u>static</u> friction. Solving for <em>µ</em> gives
<em>µ</em> = (70.0 N) / ((27.0 kg) <em>g</em>) ≈ 0.265
(b) As it's moving, the block still has the same weight and thus feels the same normal force, (27.0 kg) <em>g</em>. In order to move at a constant speed, kinetic friction must exert the same force as the push, so
<em>µ</em> (27.0 kg) <em>g</em> = 64.0 N
where <em>µ</em> is now the coefficient of <u>kinetic</u> friction. Solve for <em>µ</em> :
<em>µ</em> = (64.0 N) / ((27.0 kg) <em>g</em>) ≈ 0.242
Answer:
The internal resistance of the battery is 9.705 Ω
Explanation:
The total resistance of the circuit is
<em>Req = R + r</em>
<em> =(9 + 0.705) </em>Ω
= 9.705 Ω
Answer:
-D) Identify a question, make observations, create a hypothesis, and then set up an experiment to test the hypothesis because need to follow the steps to do the experiment properly.
Answer:
Explanation:
spring constant of spring = mg / x
= .4 x 9.8 / ( .95 - .65 )
=13.07 N / m
energy stored in spring = 1/2 k x²
= .5 x 13.07 x ( 1.2 - .65 )²
= 1.976 J
Let it goes x m beyond its equilibrium position
Total energy at initial point
= 1.976 + 1/2 m v²
= 1.976 + .5 x .4 x 1.6²
= 2.488 J
energy at final point
= mgh + 1/2 k x²
.4 x 9.8 x ( .55 + x ) + .5 x 13.07 x² = 2.488
6.535 x² + 2.156 + 3.92 x = 2.488
6.535 x² + 3.92 x - .332 = 0
x = .075 m
7.5 cm