An object accelerates 13.0 m/s2 when a force of 4.4 newtons is applied to it. What is the

A plastic film moves over two drums. During a 4-s interval the speed of the tape is increased uniformly from v0 = 2ft/s to v1 =

Ratling [72]

Answer:

Question 1)

a) The speed of the drums is increased from 2 ft/s to 4 ft/s in 4 s. From the below kinematic equations the acceleration of the drums can be determined.

$v_1 = v_0 + at \\4 = 2 + 4a\\a = 0.5~ft/s^2$

This is the linear acceleration of the drums. Since the tape does not slip on the drums, by the rule of rolling without slipping,

$v = \omega R\\a = \alpha R$

where α is the angular acceleration.

In order to continue this question, the radius of the drums should be given.

Let us denote the radius of the drums as R, the angular acceleration of drum B is

α = 0.5/R.

b) The distance travelled by the drums can be found by the following kinematics formula:

$v_1^2 = v_0^2 + 2ax\\4^2 = 2^2 + 2(0.5)x\\x = 12 ft$

One revolution is equal to the circumference of the drum. So, total number of revolutions is

$x / (2\pi R) = 6/(\pi R)$

Question 2)

a) In a rocket propulsion question, the acceleration of the rocket can be found by the following formula:

$a = \frac{dv}{dt} = -\frac{v_{fuel}}{m}\frac{dm}{dt} = -\frac{13000}{2600}25 = 125~ft/s^2$

b) $a = -\frac{v_{fuel}}{m}\frac{dm}{dt} = - \frac{13000}{400}25 = 812.5~ft/s^2$

5 0

4 years ago

The upper arm muscle is _______________ to the skin.

Nikolay [14]

Answer:

The pectoralis major, latissimus dorsi, deltoid, and rotator cuff muscles connect to the humerus and move the arm. The muscles that move the forearm are located along the humerus, which include the triceps brachii, biceps brachii, brachialis, and brachioradialis.

5 0

3 years ago

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A lump of clay whose rest mass is 4 kg is travelling at three-fifths the speed of light when it collides head-on with an identic

Harman [31]

Answer:

mass of the composite lump is 10 kg

Explanation:

given data

mass = 4 kg

to find out

mass of composite lump

solution

we know energy is conserved so

so m1 = m2 = m0 that is 4kg

and

E(1) release+ E(2) release = E(1,2) rest

so γ(1)m(1)c² + γ(2)m(2)c² = Mc² ..........................1

that why here

|v(1)| = |v(2)| = 3/5 c ......................2

and

γ = 1 / √(1 − v²/c²) .......................3

put here v = 3 and c is 5

γ = 1 /√(1 − 9/25)

γ = 5/4

so

γ(1) = γ(2) = γ = 5/4

so from equation 1

γ(1)m(1)c² + γ(2)m(2)c² = Mc²

M = 2γm0

M = 2(5/4 )(4)

M = 10 kg

so mass of the composite lump is 10 kg

7 0

4 years ago

You can jump 3 m (10 feet) off of a diving board and into a swimming pool and be uninjured. However, if you jumped from the same

Mrac [35]

Answer:

1) this is due to force due to momentum change of a body falling from such a height.

2) they move with velocity of 2.69 m/s towards the right.

Explanation:

1) in the case where one jumps 3 meters into water, the water deform on impact extending the time of impact for your body's momentum to get to zero, so that the time it takes for the momentum of your body due to your mass and your velocity to get to zero is relatively long lessening the force felt due to the impact.

For a fall from the same height onto a concrete, the concrete does not deform at all. This means that there is a very short time for your momentum to get to zero and hence the force is huge. In order to cushion this a little, your body deforms in a bid to reduce the force and this is very deadly.

This is in line with Newton's second law of motion which states that the rate of change of momentum is proportional to the force produced.

2)

M1 = 125 kg

M2 = 80 kg

V1 = 2.5 m/s

V2 = 3 m/s

From momentum conservation, total initial momentum must be equal to the total momentum after collision.

Momentum = mass x velocity.

That is,

M1V1 + M2V2 = (M1 + M2) Vf

Where Vf is their final velocity together.

Note that the masses stick together because the collision is inelastic.

Substituting and solving, we have

(125 x 2.5) + (80 x 3) = (125 + 80)Vf

312.5 + 240 = 205Vf

552.5 = 205Vf

Vf = 552.5/205 = 2.69 m/s

Note that the linebacker runner has the greater momentum 125 x 2.5 = 312.15

This means they both move to the right at velocity of 2.69 m/s

7 0

3 years ago

How does climate change lead to an increase in algal blooms? a. Decreased temperatures lead to an increase in phytoplankton grow

asambeis [7]

Answer;

B. Increased levels of carbon dioxide, a greenhouse gas, leads to increased phytoplankton growth.

Explanation;

-A combination of warm water, high nutrient levels, and adequate sunlight may cause a harmful algae bloom. These blooms may damage aquatic ecosystems by blocking sunlight and depleting oxygen that other organisms need to survive.

-Algae blooms have been increasing globally, and climate change may be playing a role in the increment. For instance, during the warm summer season or when water is warmer, some harmful types of algae to grow faster than other, more benign varieties.

-Additionally, the warmer surface water also prevents water from mixing vertically, allowing algae to grow thicker and faster.

4 0

3 years ago

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