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3 years ago

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1 answer:

Yanka [14]3 years ago

4 0

A. A stretched catapult can do work when released so it must have potential energy.

b. A stone on the ground will not move on its own ever again so it has zero energy.

c. In order to roll an object there must be a friction force between the object and the ground (otherwise it will slide)

d. To lift a stone you must overcome the weight which is the force due to gravity.

e. Work and energy are both measured in Joules.

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A cylinder that is 20 cm tall is filled with water. If a hole is made in the side of the cylinder 5 cm below the top level, how

lara31 [8.8K]

Answer:

See description

Explanation:

This is an example where we need Tornicelli's law, which states that the horizontal speed of a fluid that starts falling from an orifice is the same speed that an object acquires from free-falling.

$v = \sqrt{2gh}$

we are given:

$h_{cilinder} = 0.2 [m]\\h = 0.05 [m]\\d=0.15[m]$

the horizontal velocity of the water at the start is:

$v = \sqrt{2(9.8)(0.05)}=0.989949 [m/s]=1[m/s]$

now we need to find the time for the water drops to fall d:

as the gravity is the only force interacting with the water we have:

$y(t) = \frac{1}{2} g*t^2$

replace for y = d

$0.15 = \frac{1}{2} g*t^2=>t=\sqrt{\frac{2*0.15}{9.8}}=0.1749[s]$

now that we have t we notice that there are no horizontal forces interacting with the water, so the horizontal position is given by:

$x(t)=v*t$

Finally, we replace v and t:

$x(2.45) = 1*0.1749 = 0.1749 [m]=17.49[cm]$

4 0

4 years ago

A man pushes a box of 40kg up incline of 15°, if the man applies a horizontal force of 200N and the box moves up the plane a dis

Tatiana [17]

20 m is the correct answer

5 0

4 years ago

A car accelerates to the right from 12 m/s to 30 m/s in 6.0 s. What was its acceleration and displacement during this time inter

Scorpion4ik [409]

Answer:

Acceleration = 3m/s^2

Displacement = 126 m

Explanation:

The velocity changed from 12 to 30 m/s in 6 seconds. Using the formula for acceleration we get

(30-12)/6= 18/6= 3m/s^2

Displacement is d=.5a*t^2+v0*t

Inputting acceleration, time, and velocity leaves us with

d=1.5 * 36 + 12 * 6 = 54 + 72 = 126 m

7 0

4 years ago

If the distance separating the objects is the same for each pair which pair will have the greatest gravitational force between T

hjlf

Answer:

ur 2 sqyares out of the cicle. how many squares to get back in for example.

Explanation:

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3 years ago

A 5kg cart moving to the right with a velocity of 16 m/s collides with a concrete wall and

Kryger [21]

Explanation:

mass, m = 5kg

initial velocity, u = 16m/s

final velocuty, v = -22m/s

change in momentum, ∆p = ?

∆p = m (v-u)

5(-22-16)

5(38)

∆p = 190kgm/s

check the calculations!

8 0

3 years ago