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ycow [4]
3 years ago
9

A ball of mass m is thrown into the air in a 45° direction of the horizon, after 3 seconds the ball is seen in a direction 30° f

rom the horizon. Ignoring the friction of the air, find the initial velocity v of the ball.
Physics
1 answer:
Rzqust [24]3 years ago
3 0

Answer:

Velocity (magnitude) is 98.37 m/s

Explanation:

We use the vertical component of the initial velocity, which is:

v_{0y}=v_0*sin(45)=\frac{\sqrt{2} }{2}v_0

Using kinematics expression of vertical velocity (in y direction) for an accelerated motion (constant acceleration, which is gravity):

v_{y}=v_{0y}+a*t=\frac{\sqrt{2} }{2}v_0-9.8t

Now we need to find v_y as a function of v_0. We use the horizontal velocity, which is always the same as follow:

v_x=v_0cos(45\º)=\frac{\sqrt{2} }{2}v_0=v_{t=3}*cos(30\º) \\

We know the angle at 3 seconds:

v_y(t=3)=v_{t=3}*sin(30\º)\\v_{t=3}=\frac{v_y}{sin(30\º)}

Substitute  v_{t=3} in  v_x and then solve for  v_y

\frac{\sqrt{2} }{2}v_0=\frac{v_y*cos(30\º) }{sin(30\º)} \\v_y=\frac{\sqrt{6} }{6}v_0

With this expression we go back to the kinematic equation and solve it for initial speed

\frac{\sqrt{6} }{6} v_0 =\frac{\sqrt{2} }{2}v_0-29.4\\v_0(\frac{\sqrt{6}-3\sqrt{2}}{6} )=-29.4\\v_0=98.37 m/s

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You have two windlasses (winches) named X and Y. Windlass X drum diameter is 50cm and windlass Y drum diameter is 75cm. Both are
Blababa [14]

You have two windlasses  named X and Y. Windlass X drum diameter is 50cm and windlass Y drum diameter is 75cm. Both are hoisting a 50kg weight, Hence, X will lift faster and easier than Y

<h3>What is windlasses (winches) will lift faster?</h3>

Generally, the equation for the Torque is  mathematically given as

Torque(X)=weight x radius of drum

T=50x9.81x0.25

T=122.625 Nm

For, Torque (Y)

T=50x9.81x0.375

T=183.93 Nm

Generally, the equation for the Equation of Power is  mathematically given as

P= Torque * Angular velocity

Angular velocity (w)= 2 x pi x N/60

As a consequence, torque has an inverse relationship to speed. Because of this, the torque will decrease as the speed rises.

According to the previous statement, windlass X has a speed of lift that is at its maximum, but windlass Y has a speed that is very low.

Additionally, power is exactly proportional to torque, which means that the highest possible torque required the highest possible amount of energy and vice versa.

Therefore, X should raise at the highest possible speed while using the least amount of energy.

In conclusion, X will lift faster and easier than Y

Read more about windlasses

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4 0
1 year ago
A wave is moving at 18 m/s. If its wavelength is 3 meters, what is its frequency?
Vlada [557]

here's the solution,

we know that,

=》

wave \: speed = wavelength \times frequency

so,

=》

18 = 3 \times f

=》

f =  \dfrac{18}{3}

=》

f = 6

frequency = 6 hertz

7 0
3 years ago
A parallel plate capacitor fully charged to voltage V is connected to the battery (the voltage on the plates remains fixed). If
Papessa [141]

Charge will decreases.

A parallel plate capacitor when it is fully charged to voltage V is given as:

                    C = Q/V

The capacitance of parallel plate capacitor with two plates of Area A separated by distance d and no dielectric material between plates is

                    C = ε₀ A /d

since from above equation it shows C is proportional to Q and also C is inversely proportional to distance d.

So, ATQ when d increases C will decrease which in result decreases charge on the capacitor.

Thus,  Charge will decrease.

Learn more about capacitance here:

     brainly.com/question/17115454

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7 0
2 years ago
Does a rigid object in uniform rotation about a fixed axis satisfy the first and second conditions for equilibrium?
Vladimir [108]

Answer:

Explanation:

a rigid object in uniform rotation about a fixed axis does not satisfy both the condition of equilibrium .

First condition of equilibrium is that net force on the body should be zero.

or F net = 0

A body under uniform rotation is experiencing a centripetal force all the time so F net ≠ 0

So first condition of equilibrium is not satisfied.

Second condition is that , net torque acting on the body  must be zero.

In case of a rigid object in uniform rotation , centripetal force is applied towards the centre ie  towards the  line joining the body under rotation with the axis .

F is along r

torque = r x F

= r F sinθ

θ = 0 degree

torque = 0

Hence 2nd condition is fulfilled.

7 0
3 years ago
Two open organ pipes, sounding together, produce a beat frequency of 8.0 Hz . The shorter one is 2.08 m long. How long is the ot
s344n2d4d5 [400]

Answer:

The length of the longer pipe is L = 2.30 m

Explanation:

Given that:

Two open organ pipes, sounding together, produce a beat frequency of 8.0 Hz . The shorter one is 2.08 m long.

How long is the other pipe?

From above;

The formula for the frequency of open ended pipes can be expressed as:

f = \dfrac{nv}{2L}

where n = 1 ( since half wavelength exist between those two pipes)

v = 343 m/s  and L = 2.08 m

Thus, the shorter pipe produces a frequency of :

f = \dfrac{1*343}{2*2.08}

f = \dfrac{343}{4.16}

f =82.45 \ Hz

Also; we know that the beat frequency was given as 8.0 Hz

Then,

The lower frequency of the longer pipe = ( 82.45 - 8.0 )Hz

The lower frequency of the longer pipe = 74.45 Hz

Finally;

From the above equation; make Length L the subject of the formula. Then,

The length of the longer pipe is L = \dfrac{nv}{2f}

The length of the longer pipe is L = \dfrac{1*343}{2*74.45}

The length of the longer pipe is L = \dfrac{343}{148.9}

The length of the longer pipe is L = 2.30 m

6 0
3 years ago
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