Pls someone help me with this :(

alina1380 [7]

The solutions would be :
1. C
2. B
3. A
4. C
5. D.

3 0

3 years ago

Two children hang by their hands from the same tree branch. The branch is straight, and grows out from the tree trunk at an angl

vazorg [7]

Answer:879.29 N-m

Explanation:

Given

mass of first child $m_1=44 kg$

distance of first child from tree is $r_1=1 m$

tree is inclined at an angle of $\theta =27^{\circ}$

mass of second child $m_1=27 kg$

distance of second child from tree is $r_2=2.1 m$

Weight of first child $=m_1g=431.2 kg$

Weight of second child $=m_2g=264.6 kg$

Torque of first child weight $=m_1g\cos \theta \cdot r_1$

$T_1=44\times 9.8\times \cos 27\times 1=384.202 N-m$

Torque of second child weight $=m_2g\cos \theta \cdot r_2$

$T_2=27\times 9.8\times \cos 27\times 2.1=495.096 N-m$

Net torque $T_{net}=T_1+T_2=384.202+495.096=879.29 N-m$

6 0

3 years ago

_______is a speed in a certain direction.

Law Incorporation [45]

D. velocity
Velocity depends on speed and direction

6 0

2 years ago

An ice skater of mass m = 60 kg coasts at a speed of v = 0.8 m/s past a pole. At the distance of closest approach, her center of

IrinaVladis [17]

Answer:

1.78 rad/s

1.70344 rad/s

Explanation:

v = Velocity = 0.8 m/s

m = Mass of person = 60 kg

$r_1$ = Distance between center of mass of person and pole = 0.45 m

$r_2$ = New distance between center of mass of person and pole = 0.46 m

I = Moment of inertia

Angular speed is given by

$\omega_1=\dfrac{v}{r_1}\\\Rightarrow \omega_1=\dfrac{0.8}{0.45}\\\Rightarrow \omega_1=1.78\ rad/s$

The angular speed is 1.78 rad/s

In this system the angular momentum is conserved

$L_1=L_2\\\Rightarrow I_1\omega_1=I_2\omega_2\\\Rightarrow mr_1^2\omega_1=mr_2^2\omega_2\\\Rightarrow \omega_2=\dfrac{r_1^2\omega_1}{r_2^2}\\\Rightarrow \omega_2=\dfrac{0.45^2\times 1.78}{0.46^2}\\\Rightarrow \omega_2=1.70344\ rad/s$

The new angular speed is 1.70344 rad/s

7 0

2 years ago

Patrick is repairing the roof on his house. He uses a hammer having a mass of 1 kilogram. While working at the apex of the roof,

pav-90 [236]

Answer:

72 joules

Explanation:

The potential energy of that hammer is a function of its displacement against gravity. Considering that it fell with a velocity of 12 m/s, it was its displacement against gravity that gave it this velocity. It will continue to move until its displacement to gravity is zero.

since the body is in motion; it has converted its potential energy (mgh, m is mass, g is acceleration due to gravity, and h is the height) to kinetic energy (energy due to motion, 1/2mv^2; m = mass, v = velocity or speed)

therefore the potential energy is equal to kinetic energy

mgh = 1/2mv^2 = 1/2 *1kg* 12*12 = 72 joules.

5 0

2 years ago