1) what is SI unit of solid angle? ng

A force gives a 5.0 kg object an acceleration of 2.0 m/s 2. The same force would give a 20 kg object an acceleration of _____. 0

Oksi-84 [34.3K]

m = 5 kg

a = 2 m/s²

to find the force that accelerates the 4 kg object @ 2 m/s²

F = ma = 5 kg x 2 m/s² = 10 N

To find what acceleration 10 N would give a 20 kg object

a = F/m = 10 N/20 kg = 0.5 m/s

6 0

3 years ago

Read 2 more answers

(a) What is the cost of heating a hot tub containing 1440 kg of water from 10.0°C to 40.0°C, assuming 75.0% efficiency to take h

BaLLatris [955]

Answer:

a) $E = 6.024\,USD$ , For m kilograms, it is 4184m J., 3600000 joules, b) $i = 88.200\,A$

Explanation:

a) The amount of heat needed to warm water is given by the following expression:

$Q_{needed} = m_{w}\cdot c_{w}\cdot (T_{f}-T_{i})$

Where:

$m_{w}$ - Mass of water, measured in kilograms.

$c_{w}$ - Specific heat of water, measured in $\frac{J}{kg\cdot ^{\circ}C}$ .

$T_{f}$ , $T_{i}$ - Initial and final temperatures, measured in $^{\circ}C$ .

Then,

$Q_{needed} = (1440\,kg)\cdot \left(4184\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (40^{\circ}C - 10^{\circ}C)$

$Q_{needed} = 180748800\,J$

The energy needed in kilowatt-hours is:

$Q_{needed} = 180748800\,J\times \left(\frac{1}{3600000}\,\frac{kWh}{J} \right)$

$Q_{needed} = 50.208\,kWh$

The electric energy required to heat up the water is:

$E = \frac{50.208\,kWh}{0.75}$

$E = 66.944\,kWh$

Lastly, the cost of heating a hot tub is: (USD - US dollars)

$E = (66.944\,kWh)\cdot \left(0.09\,\frac{USD}{kWh} \right)$

$E = 6.024\,USD$

The heat needed to raise the temperature a degree of a kilogram of water is 4184 J. For m kilograms, it is 4184m J. Besides, a kilowatt-hour is equal to 3600000 joules.

b) The current required for the electric heater is:

$i = \frac{Q_{needed}}{\eta \cdot \Delta V \cdot \Delta t}$

$i = \frac{180748800\,J}{0.75\cdot (220\,V)\cdot (3.45\,h)\cdot \left(3600\,\frac{s}{h} \right)}$

$i = 88.200\,A$

7 0

3 years ago

A machine gun fires 50gm bullets at a speed of 1000m/s. the Gunner, holding the machine gun in his hand,can exert an average for

horsena [70]

Answer:

We are given:

m = 50g OR 0.05 kg

v = 1000 m/s

Force applied by the gunner in a second = 180 N

Momentum(p) of the bullet:

p = mv

p = 0.05 * 1000

p = 50 kg m/s

Finding the recoil force:

The units kg m/s are also known as 'N' (newtons)

So, we can say that the force exerted on every bullet is 50 N

According to the law of conservation of momentum, every bullet fired applies a force of 50N towards the gunner

Hence, we can say that the recoil force of every bullet is 50N

Finding the number of bullets fired in a minute:

We are given that the gunner applied an average force of 180N on the gun

we know that that can also be written as 180 kg m/s. Notice the 's' in the units of the momentum, it tells us that this force is applied every second

So, to find the amount of force applied in a minute, we can multiply it by 60

Force applied by the gunner in a minute = (60 * 180) = 10800 N

Let n be the number of bullets fired in a minute

We can say that the force applied by the gunner is equal to the force applied by a bullet times the number of bullets fired

F(gunner) = n * F(bullet)

10800 = n * 50

n = 10800/50

n = 216 bullets / minute

The gunner shoots 216 bullets in a minute

5 0

4 years ago

A pulley with a mechanical advantage of 5 will require you to pull _____ times the amount of rope.

Marat540 [252]

Answer:

It will require a force of 1/5, answer A.

Explanation:

In the attached image we can see an example of an array of pulleys that will lift a 100 kg-f load.

If we analyze pulleys A,B, and C as in the image we can check a force in the cable of 20kg-f.

In the pulley D we have three forces of 20 kg-f each and those forces plus the forces in the pulley B, sum a total of 100 kg-f (60+40). This matches the mechanical advantage (100/5) = 20 kg-f

6 0

3 years ago

indicate whether the statement is true or false the synthesis of a large collection of information that income passes well teste

Maksim231197 [3]

Answer: True

The statement " the synthesis of a large collection of information that encompasses well tested and verified hypothesis about certain aspects of natural world is known as "scientific theory".

It was proposed by Charles Darwin and Alfred Russel in the mid 19th century.

Typically, it is about the relationship between various facts and is a way of providing a concise explanation for what's been observed. A scientific theory is a well- substantiated explanation of an aspect of the natural world.

4 0

3 years ago

1) what is SI unit of solid angle?ng​

1) what is SI unit of solid angle?ng