Current enters a circuit at a:

If the effects of heat and friction are ignored, the amount of work output is always _______ the amount of work input, even when

vodomira [7]

Answer:

A

Explanation:

3 0

3 years ago

A car's position in relation to time is plotted on the graph. What is the car's average velocity for segment C? A) -4 m/s B) -0.

kotegsom [21]

Answer:

b

Explanation:

its the anwser

7 0

3 years ago

A truck, initially at rest, rolls down a frictionless hill and attains a speed of 20 m/s at the bottom. To achieve a speed of 40

Crank

Answer:

To achieve the velocity of 40 m/sec height will become 4 times

Explanation:

We have given initially truck is at rest and attains a speed of 20 m/sec

Let the mass of the truck is m

At the top of the hill potential energy is mgh and kinetic energy is $\frac{1}{2}mv^2$

So total energy at the top of the hill $=mgh+0=mgh$

At the bottom of the hill kinetic energy is equal to $\frac{1}{2}mv^2$ and potential energy will be 0

So total energy at the bottom of the hill is equal to $0+\frac{1}{2}mv^2$

Form energy conservation $mgh=\frac{1}{2}mv^2$

$v=\sqrt{2gh}$ , for v = 20 m/sec

$20=\sqrt{2\times 9.8\times h}$

Squaring both side

$19.6h=400$

h = 20.408 m

Now if velocity is 0 m/sec

$40=\sqrt{2gh}$

$19.6h=1600$

h = 81.63 m

So we can see that to achieve the velocity of 40 m/sec height will become 4 times

5 0

3 years ago

Two hockey pucks, labeled A and B, are initially at rest on asmooth ice surface and are separated by a distance of18.0 m. Simult

zlopas [31]

Answer:

8.505 m

Explanation:

Let V1 and V2 be velocities of puck A and B respectively

Since A and B move in the same direction, so the relative velocity will be V1+V2=3.5+3.9=7.4m/s

Or

Vr=7.4 m/s

Distance=S= 18 m

Time =t=?

S=Vr×t

==> t=S/Vr

==> t= 18/7.4=2.43 sec

At this time both will strike together

Distance by puck A

V1=3.5 m/s

Time=t= 2.43 sec

Distance covered=d=?

d=V1×t=3.5×2.43=8.505 m

So, puck A will cover 8.505 meters before collision

6 0

3 years ago

A ball is thrown straight upward. How does the sign of the work done by gravity while the ball is traveling upward compare with

Vlada [557]

If I’m understanding this. Th reason why the ball can resist gravity’s pull is because the force used to throw it up was greater than gravity’s pull on it. BTW, gravity’s pull is 9.8m/s. So it would have to be greater than that

8 0

3 years ago

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