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4 years ago

10

a student uses a simple machine to help lift a load.when 40N of input force is applied to the machine it is able to lift 160N .w

hat is the mechanical advantage of the machine

1 answer:

Akimi4 [234]4 years ago

3 0

4 to 1

Explanation If you look at it as a fraction 160/40 and you reduce it down as far as you can you get 4/1

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Describe a situation where kinetic energy is converted into potential energy

siniylev [52]

1. A spring or elastic can be stretched to store energy as it wants to return to rest.

2. Gravitational every can be is stored by moving a ball against gravity when lifted then released when bounced.

3. Separating two charged plates will store energy as the plates want to return to their original position.

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3 years ago

At a time t = 2.80 s , a point on the rim of a wheel with a radius of 0.230 m has a tangential speed of 51.0 m/s as the wheel sl

bonufazy [111]

Answer:

Part A) the angular acceleration is α= 44.347 rad/s²

Part B) the angular velocity is 195.13 rad/s

Part C) the angular velocity is 345.913 rad/s

Part D ) the time is t= 7.652 s

Explanation:

Part A) since angular acceleration is related with angular acceleration through:

α = a/R = 10.2 m/s² / 0.23 m = 44.347 rad/s²

Part B) since angular acceleration is related

since

v = v0 + a*(t-t0) = 51.0 m/s + (-10.2 m/s²)*(3.4 s - 2.8 s) = 44.88 m/s

since

ω = v/R = 44.88 m/s/ 0.230 m = 195.13 rad/s

Part C) at t=0

v = v0 + a*(t-t0) = 51.0 m/s + (-10.2 m/s²)*(0 s - 2.8 s) = 79.56 m/s

ω = v/R = 79.56 m/s/ 0.230 m = 345.913 rad/s

Part D ) since the radial acceleration is related with the velocity through

ar = v² / R → v= √(R * ar) = √(0.23 m * 9.81 m/s²)= 1.5 m/s

therefore

v = v0 + a*(t-t0) → t =(v - v0) /a + t0 = ( 1.5 m/s - 51.0 m/s) / (-10.2 m/s²) + 2.8 s = 7.652 s

t= 7.652 s

4 0

3 years ago

A cup containing 200 g of hot water is taken off the stove placed on the kitchen table. Initially the water is at 75Degree C. bu

8090 [49]

Answer:

ΔH = -45.1872 kJ , where negative sign signifies heat loss.

Q = ΔH = -45.1872 kJ , where negative sign signifies heat loss.

S system = -0.141 kJ/K

S surroundings = 0.1536 kJ/K

S universe = -0.141 kJ/K + 0.1536 kJ/K = 0.0126 kJ/K

Explanation:

Given:

Cp = 4. 184 J/(mole. K)

T₁ = 75 ⁰C

T₂ = 21 ⁰C

Mass of water = 200 g = 0.2 kg

Since,

$\Delta H=m\times C\times (T_f-T_i)$

ΔH = 0.2*4.184*(21-75) kJ

<u> ΔH = -45.1872 kJ , where negative sign signifies heat loss.</u>

Since the process is at constant pressure

<u> Q = ΔH = -45.1872 kJ , where negative sign signifies heat loss.</u>

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

T₁ = 75 ⁰C = 348 .15 K

T₂ = 21 ⁰C = 294.15 K

The entropy of the water is given by:

<u> S = m×Cp×ln(T₂ /T₁) </u>

S = 0.2*4.184*ln(294.15/348.15)

<u> S system = -0.141 kJ/K</u>

The heat gain by surroundings

<u> dQ = -Qreaction = 45.1872 kJ </u>

The entropy change of surroundings is

S surr = dQ/T₂ = 45.1872/294 .15

<u> S surr = 0.1536 kJ/K </u>

The entropy of universe is the sum total of the entropy of the system and the surroundings and thus,

S universe = Ssys + Ssurr

<u> S universe = -0.141 kJ/K + 0.1536 kJ/K = 0.0126 kJ/K</u>

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3 years ago

What will the stopping distance be for a 3,000-kg car if -3,000 N of force are applied when the car is traveling 10 m/s?

Harlamova29_29 [7]

F = force applied to stop the car = - 3000 N

m = mass of the car = 3000 kg

a = acceleration of the car = ?

v₀ = initial velocity of the car before the force is applied to stop it = 10 m/s

v = final velocity of the car when it comes to stop = 0 m/s

d = stopping distance of the car

acceleration of the car is given as

a = F/m

inserting the values

a = - 3000/3000

a = - 1 m/s²

using the kinematics equation

v² = v²₀ + 2 a d

inserting the values

0² = 10² + 2 (-1) d

0 = 100 - 2 d

2 d = 100

d = 100/2

d = 50 m

hence the correct choice is

C. 50 m

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3 years ago

At present, NASA is planning a mission to Europa, to try and assess its habitability. An argument might also be made for Encelad

kifflom [539]

Answer:

Jupiter

Explanation:

For this space trip, the distance to the planet must be taken into account, so Because Jupiter is much closer it should be the correct choice

.

It must also be taken into account that Saturn has a series of rings, for which the ship has a probability of colliding with one of these in one of its turns, therefore taking this into account, Jupiter must also be chosen.

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3 years ago