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3 years ago

I've had several mental breakdowns please help me

Physics

1 answer:

sesenic [268]3 years ago

4 0

Answer:

The efficiency of the system is 63.7 %

Explanation:

Given;

input power of the motor, = 1.5 kW = 1,500 W

mass of the car lifted, m = 1300 kg

height through which the car was lifted, h = 1.8 m

time, t = 24 s

The output power of the motor is calculated as;

Output Power = F x v

= (mg) x (d/t)

= (1300 x 9.8) x (1.8 / 24)

= 12,740 x 0.075

= 955.5 W

The efficiency of the system is calculated as;

$E = \frac{0utput \ power}{1nput \ power} \times \ 100\%\\\\E = \frac{955.5}{1500} \times \ 100\% \\\\E = 63.7 \ \%$

The correct answer is 63.7%

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A tennis ball was thrown straight up with initial velocity of 22.5 m/s. How high does the ball rise

kiruha [24]

Answer:

$h_m=25.8\ m$

Explanation:

<u>Vertical Launch Upwards</u>

In a vertical launch upwards, an object is launched vertically up without taking into consideration friction with the air.

If vo is the initial speed and g is the acceleration of gravity, the maximum height reached by the object is given by:

$\displaystyle h_m=\frac{v_o^2}{2g}$

The tennis ball was thrown straight up with a speed of v0=22.5 m/s. The acceleration of gravity is g=9.81\ m/s^2, thus:

$\displaystyle h_m=\frac{22.5^2}{2\cdot 9.81}$

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3 years ago

How many newton-meters are equal to 1600 joules

Salsk061 [2.6K]

1 Joule IS 1 newton-meter.

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3 years ago

An apple with mass 0.4 kg is hanging at rest from the lower end of a light vertical rope. A dart of mass 0.1 kg is shot vertical

Sholpan [36]

Answer:

The speed of the apple just after the collision is 1m/s

Explanation:

Since the two bodies collided, we will apply the law of conservation of momentum to find their common velocity which states that the sum of momentum of the bodies before collision is equal to the sum of momentum of the bodies after collision. After collision both bodies will move with a common velocity v.

Given momentum = mass × velocity

Initial momentum of the 0.4kg apple hanging at rest will be;

Momentum = 0.4kg×0m/s = 0kgm/s (the velocity of apple is 0m/s since it is hanging at rest)

Initial momentum of the 0.1kg dart moving with speed of 5m/s will be;

Momentum of dart = 0.1kg × 5m/s

Momentum of dart = 0.5kgm/s

Momentum of the bodies after collision will give;

Momentum after collision = (0.4kg+0.1kg) × v (v is their common velocity)

Momentum after collision = 0.5v

Using the law of conservation of momentum to calculate their common velocity, we will have;

0+0.5 = 0.5v

0.5 = 0.5v

v = 0.5/0.5

v = 1m/s

Therefore the speed of both bodies after collision is 1m/s which will also serve as the speed of the apple after collision.

5 0

3 years ago

Read 2 more answers

a 5.00 × 105 kg rocket is accelerating straight up. Its engines produce 1.50 × 107 of thrust, and air resistance is 4.50 × 106 N

Angelina_Jolie [31]

This one is simple :)

use the equation F = ma and then re-arrange for a.

a = F / m

But there is a trick, so be careful. the question gives you wind resistance. Simply subtract the wind resistance from the thrust of the rocket to get the net force upward.

$1.50 * 10^7N - 4.5 8 10^6N = 1.05 * 10^7N$

So,

$a = \frac{F}{m} = \frac{1.05*10^7N}{5.00*10^5kg}$

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3 years ago

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3 years ago