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3 years ago

What is the velocity of a penny dropped from the roof after 5 seconds?

Physics

1 answer:

Ksivusya [100]3 years ago

4 0

Answer:

49 m/s

Explanation:

Acceleration = velocity / time

You should know accleration due to gravity is 9.8 m/s^2 and you're given t = 5, so you can solve for velocity:

9.8 = v / 5

v = 49

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A uniform solid disk of mass 5.00 kg and diameter 47.0 cm starts from rest and rolls without slipping down a 40.0 ∘ incline that

saveliy_v [14]

Answer:

The speed it reaches the bottom is

$v=6.51m/s$

Explanation:

Given: $m=5.0kg$ , $r=47cm\frac{1m}{100cm}=0.47m$

Using the conservation of energy theorem

$U_i=K_E+K_{ER}$

$m*g*h=\frac{1}{2}*m*v^2+\frac{1}{2}*I*w^2$

$v=r*w$ , $I=\frac{1}{2}*m*r^2$

$m*g*h=\frac{1}{2}*m*(r*w)^2 +\frac{1}{2}*[\frac{1}{2} *m*r^2]*w^2$

$m*g*h=\frac{3}{4}*m*r^2*w^2$

$g*h=\frac{3}{4}*r^2*w^2$

Solve to w'

$w^2=\frac{4*g*h}{3*r^2}$

$h=x*sin(30)=6.5m*sin(30)=3.25m$

$w=\sqrt{\frac{4*9.8m/s^2*3.25m}{3*(0.235m)^2}}$

$w=27.74rad/s$

$v=27.74rad/s*0.235m=6.51m/s$

7 0

3 years ago

A particle executes simple harmonic motion with an amplitude of 2.18 cm.

Bogdan [553]

Answer:

The positive displacement from the midpoint of its motion at the speed equal one half of its maximum speed is 3.56 cm.

Explanation:

Maximum speed is :

v (max) = Aω

Speed v at any displacement y is given by

$v^{2}$ = $w^{2}$ ( $A^{2}$ - $y^{2}$ ) ........................................................ i

And,

v = $\frac{1}{2}$ v (max)

or, 2 × v = Aω .................................................... ii

Eliminating ω from equations i and ii,

$\frac{1}{4}$ $A^{2}$ $w^{2}$ = $w^{2}$ ( $A^{2}$ - $y^{2}$ )

or, $y^{2}$ = ( $\frac{3}{4}$ ) $A^{2}$ =( $\frac{3}{4}$ ) $2.18^{2}$

or, y = 3.56 cm.

3 0

3 years ago

Which of the following is an important step in the process of conflict resolution?

4vir4ik [10]

A would be the correct answer. Its the only one to make sense since you are trying to solve the conflict!

7 0

3 years ago

Read 2 more answers

Ana walks from 4 m to 200 cm. Which of the following statements is true about

Gemiola [76]

Distance=2m

because 200cm = 2m
so 4m-2m=2m

3 0

3 years ago

Light strikes a 5.0-cm thick sheet of glass at an angle of incidence in air of 50°. the sheet has parallel faces and the glass h

mestny [16]

<span>Answer: sin(incidence)/sin(refraction) = n_refraction/n_incidence sin(50) / sin(x) = 1.5 / 1 sin(50)/1.5 = sin(x) sin(x) = 0.511 x = 30.71o B] 50 degrees, same as the angle going in. You can show that by reversing the steps in A. sin(30.7)/sin(x) = 1/1.5 C] The glass is 5 cm thick. The reference angle = 30.7o Tan(30.7) = displacement / thickness Tan(30.7) = x / 5 5*sin(30.7) = x x = 2.97 cm which is the displacement.</span>

4 0

3 years ago