The number of significant figures in the measurement 0.000 305 kg is

A cylindrical rod 21.5 cm long with a mass of 1.20 kg and a radius of 1.50 cm has a ball of diameter of 6.90 cm and a mass of 2.

Sergeeva-Olga [200]

Answer

given,

length of rod = 21.5 cm = 0.215 m

mass of rod (m) = 1.2 Kg

radius, r = 1.50

mass of ball, M = 2 Kg

radius of ball, r = 6.90/2 = 3.45 cm = 0.0345 m

considering the rod is thin

$I = \dfrac{1}{3}M_{rod}L^2 + [\dfrac{2}{5}M_{ball}R^2+M_{ball}(R+L)^2]$

$I = \dfrac{1}{3}\times 1.2 \times 0.215^2 + [\dfrac{2}{5}\times 2 \times 0.0345^2+2\times (0.0345 +0.215)^2]$

I = 0.144 kg.m²

rotational kinetic energy of the rod is equal to

$KE = M_{rod}g\dfrac{L}{2} + M_{ball}g(L+R)^2$

$KE = 1.2 \times 9.8 \times \dfrac{0.215}{2} + 2\times 9.8\times (0.215+0.0345)^2$

KE = 6.15 J

b) using conservation of energy

$K_f + U_f = K_i + U_i + \Delta E$

$\dfrac{1}{2}I\omega^2+ 0=0 + 6.15+0$

$\dfrac{1}{2}\times 0.144 \times \omega^2= 6.15$

ω = 9.25 rad/s

c) linear speed of the ball

v = r ω

v = (L+R )ω

v = (0.215+0.0345) x 9.25

v =2.31 m/s

d) using equation of motion

v² = u² + 2 g h

v² = 0 + 2 x 9.8 x 0.248

v = √4.86

v =2.20 m/s

speed attained by the swing is more than free fall

% greater = $\dfrac{2.31-2.20}{2.20}\times 100$

= 5 %

speed of swing is 5 % more than free fall

6 0

3 years ago

How do uplift and erosion help to form a batholith?

saul85 [17]

<span>the correct answer would be <u>by exposing a large body of igneous rock to the surface

</u></span>

6 0

3 years ago

Read 2 more answers

A uniform rod of mass M and length L can pivot freely at one end. Initially, the rod is oriented vertically above the pivot, in

Leya [2.2K]

Answer:

The speed of its center of mass = $\sqrt{\frac{3}{2}gL}$

Explanation:

Consider the potential energy at the level of center of mass of rod below the pivot=0

Mass of uniform rod=M

Length of rod=L

The rotational inertia about the end of a uniform rod= $\frac{1}{3}ML^2$

Kinetic energy at the level of center of mass of rod below the pivot= $\frac{1}{2}I\omega^2$

Kinetic energy at the level of center of mass of rod above the pivot=0

Potential energy at the level of center of mass of rod above the pivot=mgh

We have to find the center of mass ( in terms of g and L).

According to conservation of law of energy

Initial P.E+Initial K.E=Final P.E+Final K.E

$mgh+0=0+\frac{1}{2} I\omega^2$

Where $K.E=\frac{1}{2} I\omega^2$

I=Moment of inertia

$\omega$ =Angular velocity

Substitute the values then we get

$MgL=\frac{1}{2}\times \frac{1}{3}ML^2\omega^2$

$\omega^2=\frac{6g}{L}$

Now, we know that $\omega=\frac{v}{r}$ , $r=\frac{L}{2}$

Substitute the values then we get

$\frac{v^2}{(\frac{L}{2})^2}=\frac{6g}{L}$

$\frac{v^24}{L^2}=\frac{6g}{L}$

$v^2=\frac{6g\times L^2}{4L}$

$v^2=\frac{3gL}{2}$

$v=\sqrt{\frac{3}{2}gL}$

Hence, the speed of its center of mass = $\sqrt{\frac{3}{2}gL}$

4 0

4 years ago

(0 10 40 20 30 50 70 80) (90 100 110 120 130 140). Which end of the scale (left or right) has the loudest sounds?

gregori [183]

I think 140 would be the loudest.

8 0

2 years ago

Which circle passes through more continents antarctic or arctic

Alex787 [66]

Answer:Arctic circle

Explanation:

Arctic circle is one of the circles of latitude. It is located at the northern region if the equator and passes through more than one continent. These continent includes: North Asia,

Northern America, and

Europe.

In these continent, it passes through eight known counties. These countries includes: Canada, Russia, Norway, Sweden, Finland, Denmark, Alaska and Iceland. It covers 4% of the Earth surface and it's climatic conditions are extreme.

5 0

4 years ago