A measure of how far an object has moved from a starting point

an Olympic runner leaps over a hurdle.if the runner initial vertical speed is 2.2m/s how much will the runners center of mass be

Snowcat [4.5K]

Supposing the runner is condensed to a point and moves upward at 2.2 m/s.
It takes a time = 2.2/g = 2.2/9.8 = 0.22 seconds to increase to max height.
Now looking at this condition in opposite - that is the runner is at max height and drops back to earth in 0.22 s (symmetry of this kind of motion).
From what height does any object take 0.22 s to fall to earth (supposing there is no air friction)?
d = 1/2gt²= (0.5)(9.8)(0.22)²= 0.24 m

7 0

2 years ago

Skater begins to spend with arms held out at shoulder height. The skater wants to match the speed of the spin to the beat of the

Aleksandr [31]

Answer:

the moment of inertia with the arms extended is Io and when the arms are lowered the moment

I₀/I > 1 ⇒ w > w₀

Explanation:

The angular momentum is conserved if the external torques in the system are zero, this is achieved because the friction with the ice is very small,

L₀ = L_f

I₀ w₀ = I w

w = $\frac{I_o}{I}$ w₀

where we see that the angular velocity changes according to the relation of the angular moments, if we approximate the body as a cylinder with two point charges, weight of the arms

I₀ = I_cylinder + 2 m r²

where r is the distance from the center of mass of the arms to the axis of rotation, the moment of inertia of the cylinder does not change, therefore changing the distance of the arms changes the moment of inertia.

If we say that the moment of inertia with the arms extended is Io and when the arms are lowered the moment will be

I <I₀

I₀/I > 1 ⇒ w > w₀

therefore the angular velocity (rotations) must increase

in this way the skater can adjust his spin speed to the musician.

7 0

3 years ago

Severus Snape knows that density of his powder is 3.00 g/cm3 . He also knows he needs 3.00 cm3 of this powder. What mass in gram

harina [27]

Answer:

He requires 1 gram of mass.

Explanation:

The density is defined as:

$\rho = \frac{m}{V}$ (1)

Where m is the mass and V is the volume.

Then, m can be isolated from equation 1 in order to determine the mass.

$m = \rho \cdot V$ (2)

$m = (3.00g/cm^{3})(3.00cm^{3})$

$m = 1g$

Hence, he requires 1 gram of mass.

8 0

3 years ago

What does vitamin c do for our body?

Ksju [112]

Answer:

necessary for the growth, development and repair of all body tissues. it's involved in many body functions, including formation of collagen, absorption of iron, the proper functioning of the immune system, wound healing, and the maintenance of cartilage, bones, and teeth.

Explanation:

6 0

2 years ago

Read 2 more answers

Luis wants to compare the density of three solid objects that are different shapes and sizes. What information does he need to m

tatyana61 [14]

Answer:

u need to make sure that comparison is = to shapes and then find the shapes sizes and add them

7 0

2 years ago