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Natasha_Volkova [10]

3 years ago

13

A train accelerates to a velocity of 500 m/s over time of 2s. The acceleration it experienced was 50m/s2. What was its initial v

elocity?

1 answer:

ValentinkaMS [17]3 years ago

7 0

Explanation:

We know ,

v = u + at
u = v - at
u = 500 - 2*50
u = 400 m/s

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Answer:

4.4 M/s

Explanation:

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3 years ago

A cannon, positioned on a hill, shoots a cannonball horizontally at 23 m/s. The cannonball hits the stone wall 1.96 m below the

irina [24]

Answer: 14. 49 m

Explanation:

We can solve this problem with the following equations:

$x=V_{o} cos \theta t$ (1)

$y-y_{o}=V_{o} sin \theta t-\frac{1}{2}gt^{2}$ (2)

Where:

$x$ is the horizontal distance between the cannon and the ball

$V_{o}=23 m/s$ is the cannonball initial velocity

$\theta=0\°$ since the cannonball was shoot horizontally

$t$ is the time

$y=0$ is the final height of the cannonball

$y_{o}=1.96 m$ is the initial height of the cannonball

$g=9.8 m/s^{2}$ is the acceleration due gravity

Isolating $t$ from (2):

$t=\sqrt{-\frac{2(y-y_{o})}{g}}$ (3)

$t=\sqrt{-\frac{2(0 m-1.96 m)}{9.8 m/s^{2}}}$ (4)

$t=0.63 s$ (5)

Substituting (5) in (1):

$x=(23 m/s) cos(0\°) 0.63 s$ (6)

Finally:

$x=14.49 m$

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3 years ago

The magnetic field at the equator points north. if you throw a positively charged object (for example, a baseball with some elec

asambeis [7]

Recall the equation for magnetic force:

F = qv x B *x is cross product, not separate variable!

If the magnetic field points towards N and you throw E, then the magnetic force would point up, or out of the page. Use the right-hand rule. You point your finger towards the direction of the object, and curl your finger to the magnetic field. Your thumb is the direction of the magnetic force.

Hope this helps!

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4 years ago

A traffic light of weight 100 N is supported by two ropes that make 30-degree angle with the horizontal. What is the vertical co

alina1380 [7]

Answer:

$T_{vertical} = 50 N$

Explanation:

given,

traffic light weight = 100 N

angle at which the rope is supported = 30°

vertical component of force = ?

$2 T sin \theta= W$

$2 T sin 30^0= 100$

$T = \dfrac{100}{2 sin 30^0}$

$T = 100\ N$

$T_{vertical} = T sin 30^0$

$T_{vertical} = 100\times \dfrac{1}{2}$

$T_{vertical} = 50 N$

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4 years ago

What is the half-life of a compound if 75 percent of a given sample of the compound decomposes in 60 min? assume first-order kin

LenKa [72]

The amount left of a given substance can be calculated through the equation,
A = (A0) x 0.5^n/h
From the given scenario,
A/A0 = 0.75 = 0.5*(60/h)
The value of h from the equation is 144.565 minutes.

6 0

4 years ago