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2 years ago

True or False: An example of an Isometric movement is a plank. please help 2 mins left! PE

Physics

2 answers:

gtnhenbr [62]2 years ago

6 0

Answer: The answer is true:)

Anon25 [30]2 years ago

5 0

Answer:

Yes

Explanation:

The plank (also called a front hold, hover, or abdominal bridge) is an isometric core strength exercise that involves maintaining a position similar to a push-up for the maximum possible time

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If a substance is changing from a vapor to a liquid, like steam on a mirror, it is said to be _______.

NARA [144]

Answer:

condensing

Explanation:

Condensing is the word used to indicate the change of state of a substance from vapor to liquid, as in this case. During condensation, the substance releases thermal energy to the environment, therefore the kinetic energy of the molecules in the vapor decreases until they become closer to each other and they start to be affected by the intermolecular forces and so the substance becomes a liquid.

8 0

3 years ago

Read 2 more answers

Can someone help me on question 1?

grigory [225]

In question 1, both of your answers are correct, but I don't understand the process you went through in the 'a' part.

R = v/I . That's a correct formula.
But it doesn't help you in this form, because you need to find I
So turn it into a helpful form ... Solve it for I, so it says I=something.

R= v/I

Multiply each side by I : R I = V.

Now divide each side by R: I= V/R .
THERE'S the equation you want.

I = V / R

I = 1.5 / 10 = 0.15 Amp.

That's slightly cleaner, although I don't really understand what you were actually thinking in that part.

But again ... You answered both parts correctly, and your process in b is fine.

6 0

3 years ago

An athlete executing a long jump leaves the ground at a 28.0º angle and travels 7.80 m. (A) What was the takeoff speed?

Naddika [18.5K]

Answer:

9.6 m/s

Explanation:

Angle of projection, θ = 28°

Horizontal distance, R = 7.8 m

Let the velocity of projection is given by u.

The formula used to find the velocity of projection is given by

$R=\frac{u^{2}Sin2\theta }{g}$

$7.8=\frac{u^{2}Sin\left (2\times 28 \right ) }{9.8}$

$7.8=\frac{u^{2}\times 0.829}{9.8}$

u = 9.6 m/s

Thus, the velocity of projection is 9.6 m/s.

7 0

2 years ago

During an auto accident, the vehicle’s air bags deploy and slow down the passengers more gently than if they had hit the windshi

Allushta [10]

Answer:

d = 0.38 m

Explanation:

As we know that the person due to the airbag action, comes to a complete stop, in 36 msec or less, and during this time, is decelerated at a constant rate of 60 g, we can find the initial velocity (when airbag starts to work), as follows:

vf = v₀ -a*t

If vf = 0, we can solve for v₀:

v₀ = a*t = 60*9.8 m/s²*36*10⁻³s = 21.2 m/s

With the values of v₀, a and t, we can find Δx, applying any kinematic equation that relates all of some of these parameters with the displacement.

Just for simplicity, we can use the following equation:

$vf^{2} -vo^{2} = 2*a*d$

where vf=0, v₀ =21.2 m/s and a= -588 m/s².

Solving for d:

$d = \frac{-vo^{2}}{2*a} = \frac{(21.2m/s)^{2} }{2*588 m/s2} =0.38 m$

⇒ d = 0.38 m

5 0

3 years ago

Read 2 more answers

An earthquake emits both S-waves and P-waves which travel at different speeds through the Earth. A P-wave travels at 9 000 m/s a

Cerrena [4.2K]

Assuming constant speeds, the P-wave covers a distance d in time t such that

9000 m/s = d/(60 t)

while the S-wave covers the same distance after 1 more minute so that

5000 m/s = d/(60(t + 1))

Now,

d = 540,000 t

d = 300,000(t + 1) = 300,000 t + 300,000

Solve for t in the first equation and substitute it into the second equation, then solve for d :

t = d/540,000

d = 300,000/540,000 d + 300,000

4/9 d = 300,000

d = 675,000

So the earthquake center is 675,000 m away from the seismic station.

6 0

3 years ago