Answer:A block rests on a horizontal, frictionless surface. A string is attached to the block, and is pulled with a force of 45.0 N at an…
Explanation:
The acceleration should 5.4 m/s^2
a) At a position of 2.0m, the Initial energy is
all made up of the potential energy=m*g*hi<span>
and meanwhile at 1.5 all its energy is also potential energy=m*g*hf
The percentage of energy remaining is E=m*g*hi/m*g*hf x 100
and since mass and gravity are constant so it leaves us with
just E=hi/hf
which 1.5/2.0 x100= 75% so we see that we lost 25% of the
energy or 0.25 in fraction
b) Here use the equation vf^2=vi^2+2gd
<span>where g is gravity, vf is the final velocity and vi is the
initial velocity while d is the distance travelled
so in here we are looking for the vi so let us isolate that
variable
we know that at maximum height or peak, the velocity is 0 so
vf is 0
therefore,</span></span>
vi =sqrt(-2gd) <span>
vi =sqrt(-2x-9.81x1.5) </span>
<span>vi =5.4 m/s
<span>c) The energy was converted to heat due to friction with the
air and the ground.</span></span>
430m. We use the displacement formula x=v*t+1/2*a*t^2. Set upward to be the positive direction, so v=6m/s, a=-g=-9.8m/s^2 (gravity is pulling the object down), and t=10s. The displacement is -h(it's negative because the ending point is the ground, which is negative relative to the starting point). -h=60-4.9*100, h=430 m.
