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3 years ago

Does sit-ups reduce belly fat?

Physics

2 answers:

Lemur [1.5K]3 years ago

4 0

Yes it does because it exercises the muscles :))

Naddik [55]3 years ago

3 0

It does. When you are doing sit ups, it makes your core work and if you have a good strong core then you are burning fat. <span />

You might be interested in

A heavy solid disk rotating freely and slowed only by friction applied at its outer edge takes 120 seconds to come to a stop.

alisha [4.7K]

Answer:

The time is 16 min.

Explanation:

Given that,

Time = 120 sec

We need to calculate the moment of inertia

Using formula of moment of inertia

$I=\dfrac{1}{2}MR^2$

If the disk had twice the radius and twice the mass

The new moment of inertia

$I'=\dfrac{1}{2}\times2M\times(2R)^2$

$I'=8I$

We know,

The torque is

$\tau=F\times R$

We need to calculate the initial rotation acceleration

Using formula of acceleration

$\alpha=\dfrac{\tau}{I}$

Put the value in to the formula

$\alpha=\dfrac{F\times R}{\dfrac{1}{2}MR^2}$

$\alpha=\dfrac{2F}{MR}$

We need to calculate the new rotation acceleration

Using formula of acceleration

$\alpha'=\dfrac{\tau}{I'}$

Put the value in to the formula

$\alpha=\dfrac{F\times R}{8\times\dfrac{1}{2}MR^2}$

$\alpha=\dfrac{2F}{8MR}$

$\alpha=\dfrac{\alpha}{8}$

Rotation speed is same.

We need to calculate the time

Using formula angular velocity

$\Omega=\omega'$

$\alpha\time t=\alpha'\times t'$

Put the value into the formula

$\alpha\times120=\dfrac{\alpha}{8}\times t'$

$t'=960\ sec$

$t'=16\ min$

Hence, The time is 16 min.

5 0

3 years ago

A merry-go-round a.k.a "the spinny thing" is rotating at 15 RPM, and has a radius of 1.75 m

arlik [135]

Answer:

A.) 4 revolution

B.) 0.2 revolution

C.) 4 seconds

D.) 2.75 m/s

Explanation:

Given that a merry-go-round a.k.a "the spinny thing" is rotating at 15 RPM, and has a radius of 1.75 m

Solution

1 revolution = 2πr

Where r = 1.75m

A. How many revolutions will it make in 3 minutes?

(2π × 1.75) / 3

10.9955 / 3

3.665 RPM

Number of revolution = 15 / 3.665

Number of revolution = 4 revolution

B. How many revolutions will it make in 10.0 seconds?

First convert 10 seconds to minutes

10/60 = 0.167 minute

(2π × 1.75) / 0.167

10.9955 / 0.167

65.973

Number of revolution = 15 / 65.973

Number of revolution = 0.2 revolution

C. How long does it take for a person to make 1 complete revolution?

15 = 1 / t

Make t the subject of formula

t = 1/15

t = 0.0667 minute

t = 4 seconds

D. What is the velocity in m/s of person standing on its edge?

Velocity in m/ s will be:

Velocity = (15 × 2pi × r) / 60

Velocity = 164.9334 / 60

Velocity = 2.75 m/s

8 0

3 years ago

What happens to the visible radiation produced by new stars within a molecular cloud?

Eduardwww [97]

The visible radiation produced by new stars within a molecular cloud get absorbed by dust grains and heats up the cloud

A molecular cloud is an interstellar cloud of gas and dust in which molecules can form, the most common of which is hydrogen .

The formation of stars occurs exclusively within molecular clouds because of their low temperatures and high densities, because the gravitational force acting to collapse the cloud must exceed the internal pressures that are acting "outward" to prevent a collapse.

Visible radiation are absorbed by dust grains and heats up the cloud as it cannot penetrate through the cloud instead get absorbed by the cloud . Newly formed stars are visible nearby, their images reddened by blue light which got scattered by the pervasive dust.

To learn more about molecular clouds here

brainly.com/question/3459894

#SPJ4

6 0

2 years ago

While water skiing behind her father’s boat, Letty is pulled at constant speed by a force of 164 N from the tow rope that makes

kap26 [50]

Answer:

0.265

Explanation:

Draw a free body diagram. There are four forces:

Normal force Fn pushing up.

Weight force mg pulling down.

Tension force T at an angle θ.

Friction force Fn μ pushing left.

Sum the forces in the y direction:

∑F = ma

Fn + T sin θ − mg = 0

Fn = mg − T sin θ

Sum the forces in the x direction:

∑F = ma

T cos θ − Fn μ = 0

Fn μ = T cos θ

μ = T cos θ / Fn

μ = T cos θ / (mg − T sin θ)

Given T = 164 N, θ = 10.0°, m = 65.0 kg, and g = 9.8 m/s²:

μ = (164 N cos 10.0°) / (65.0 kg × 9.8 m/s² − 164 N sin 10.0°)

μ = 0.265

7 0

3 years ago

A simple pendulum makes 120 complete oscillations in 3.00 min at a location where g 5 9.80 m/s2. Find (a) the period of the pend

choli [55]

Answer:

(a) 1.5 second

(b) 0.56 m

Explanation:

Pendulum makes 120 oscillations in 3 min that means in 180 seconds

time taken by the pendulum to complete one oscillation is called time period.

(a) So, the time period is 180 / 120 = 1.5 second

T = 1.5 second

Thus, the time period of the pendulum is 1.5 second.

(b) g = 9.8 m/s^2

The formula for the time period is given by

$T =2\pi \sqrt{\frac{L}{g}}$

Where, L be the length of pendulum

$1.5 =2\times 3.14 \sqrt{\frac{L}{9.8}}$

$0.057= {\frac{L}{9.8}}$

L = 0.56 m

Thus, the length of the pendulum is 0.56 m .

6 0

3 years ago