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2 years ago

A body from the top of a 180 m high mountain is abandoned. Disregarding air resistance and adopting g = 10m / s2, determine:

Physics

1 answer:

elena55 [62]2 years ago

4 0

Answer:

1) 6 seconds

2) 60 m/s

Explanation:

Given:

Δy = 180 m

v₀ = 0 m/s

a = 10 m/s²

1) Find t.

Δy = v₀ t + ½ at²

180 m = (0 m/s) t + ½ (10 m/s²) t²

t = 6 s

2) Find v.

v² = v₀² + 2aΔy

v² = (0 m/s)² + 2 (10 m/s²) (180 m)

v = 60 m/s

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If Galileo drops a cannon ball from the 60 meter high) Leaning Tower of Pisa, how fast will it be moving when it hits the ground

viva [34]

Answer:

When the ball hits the ground, the velocity will be -34 m/s.

Explanation:

The height and velocity of the ball at any time can be calculated using the following equations:

y = y0 + v0 · t + 1/2 · g · t²

v = v0 + g · t

Where:

y = height of the ball at time "t".

y0 = initial height.

v0 = initial velocity.

t = time.

g = acceleration due to gravity. (-9.8 m/s² considering the upward direction as positive).

v = velocity at time "t".

If we place the origin of the frame of reference on the ground, when the ball hits the ground its height will be 0. Then using the equation of height, we can calculate the time it takes the ball to reach the ground:

y = y0 + v0 · t + 1/2 · g · t²

0 = 60 m + 0 m/s · t - 1/2 · 9.8 m/s² · t²

0 = 60 m - 4.9 m/s² · t²

-60 m / -4.9 m/s² = t²

t = 3.5 s

Now, with this time, we can calculate the velocity of the ball when it reaches the ground:

v = v0 + g · t

v = 0 m/s - 9.8 m/s² · 3.5 s

v = -34 m/s

When the ball hits the ground, the velocity will be -34 m/s.

5 0

3 years ago

Which statements correctly describe matter? Select all that apply.

strojnjashka [21]

Answer:

I hope these is correct

3 0

2 years ago

A dog leaps horizontally off a 70 m cliff with a speed of 6 m/s, how far from the base will the dog land?

iris [78.8K]

Answer:

$\Delta x=22.67786838m$

Explanation:

Let's use projectile motion equations. First of all we need to find the travel time. So we are going to use the next equation:

$y-y_0=v_o*sin(\theta)*t-\frac{1}{2}*t^2$ (1)

Where:

$y=Final\hspace{3}position\hspace{3}at\hspace{3}y-axis$

$y_o=Initial\hspace{3}position\hspace{3}at\hspace{3}y-axis$

$v_o=initial\hspace{3}velocity$

$t=travel\hspace{3}time$

$g=gravity\hspace{3}constant$

$\theta=Initial\hspace{3}launch\hspace{3}angle$

In this case:

$\theta=0$

Because the dog jumps horizontally

Let's asume the gravity constant as:

$g=9.8$

$y=0$

Because when the dog reach the base the height is 0

$y_o=70$

$v_o=6$

Now let's replace the data in (1)

$y_o-\frac{1}{2} *(9.8)*t^2+70$

Isolating t:

$t=\pm\sqrt{\frac{2*70}{9.8} } =3.77964473$

Finally let's find the horizontal displacement using this equation:

$\Delta x=v_o*cos(\theta)*t$

Replacing the data:

$\Delta x=6*1*3.77964473=22.67786838m$

8 0

2 years ago

Please help me match these words to the correct sentence

Mariana [72]

I got you...2.)d 3.)a 4.) e

8 0

2 years ago

Two wires are hanging horizontally and parallel to one another and they are spaces 5.4 cm apart. The bottom wire carries a curre

xxMikexx [17]

Answer:

299.11 A

Explanation:

You first equal the magnetic force on the upper wire with the gravitational force:

$F_E=F_g\\\\i_1LB=Mg$ ( 1 ) (first term is the magnetic force produced by the magnetic force of the second wire)

i1: current of the upper wire

L: length

M: mass of the upper wire

B: magnetic field generated by the second wire

Next, you calculate the magnetic field produced by the other wire:

$B=\frac{\mu_o i_2}{2\pi r}$ (2)

i2: current of the second wire

r: distance between wires

mo: magnetic permeability of vacuum = 4pi*10^-7 T/A

Next, you replace the expression (2) into the expression (1) in order to obtain an expression for i2:

$i_1L(\frac{\mu_oi_2}{2\pi r})=Mg\\\\i_2=\frac{M}{L}\frac{2\pi r g}{\mu_oi_1}$

M/L = is the mass per unit length of the first wire

Finally, you replace the values of the parameters:

$i_2=(2.6*10^{-4}kg/m)\frac{2\pi (0.054m)(9.8m/s^2)}{(4\pi*10^{-7}T/A)(2.3A)}\\\\i_2=299.11A$

hence, the current in the second wire must be 299.11A

6 0

2 years ago