Constant speed along the inclined surface = 30 m / 4 s = 7.5 m/s

Vertical speed = inclined speed * sin(45) = 7.5 *√2 / 2 = 5.3 m/s

Answer: 5.3 m/s

8 0

3 years ago

Out of all the mass and energy in the universe, ordinary matter (the stuff that makes up stars and gas, and all the things we in

MrMuchimi

Answer:

About 5 % of the universe is visible.

Estimates are that 68 % of the universe consists of "dark energy" and 27% of the universe consists of "dark matter". Currently 95 % of the universe is not currently visible to the scientists involved (cannot be explained by means that we know).

5 0

2 years ago

A skater rotates with her arms crossed at an angular speed of 8.0 rad/s and she has a moment of inertia of 100 kg/m2. She extend

solong [7]

Answer:

When her hands extends, her momen of inertia is $4.28\ kg-m^2$ .

Explanation:

Given that,

Initial angular speed, $\omega_i=8\ rad/s$

Initial moment of inertia, $I_1=100\ kg-m^2$

Final angular speed, $\omega_f=7\ rad/s$

Initially, a skater rotates with her arms crossed and finally she extends her arms. The momentum remains conserved. Using the conservation of momentum as :

$I_1\omega_1=I_2\omega_2$

$I_2$ is final moment of inertia

$I_2=\dfrac{I_1\omega_1}{\omega_2}\\\\I_2=\dfrac{100\times 8}{7}\\\\I_2=114.28\ kg-m^2$

So, when her hands extends, her momen of inertia is $4.28\ kg-m^2$ . Hence, this is the required solution.

7 0

3 years ago