All categories

4 years ago

How much heat must be removed from 0.90 kg of water at 0 ∘c to make ice cubes at 0 ∘c?

1 answer:

4 0

<span>3.0x10^5 Joules Since the water is already at the freezing point, we just need to remove the enthalpy of fusion for water, which is 333.55 J/g. So: 0.90 kg * 1000 g/kg * 333.55 J/g = 300195 J Rounding to 2 significant figures means we have to remove 3.0x10^5 Joules of heat to freeze the water.</span>

You might be interested in

Determine the moment of inertia of a uniform solid sphere of mass M and radius R about an axis that is tangent to the surface of

Inessa05 [86]

Answer:

$I = \frac{7}{5}MR^2$

Explanation:

For answer this we will use the paralell axis theorem:

I= $I_{cm} + Md^2$

Where $I_{cm}$ is the moment of inertia of the center of mass, M is the mass of the sphere and d is the distance between the center of mass and the axis for rotate, then:

$I = \frac{2}{5}MR^2 +MR^2$

$I = \frac{7}{5}MR^2$

4 0

3 years ago

Ben climbs a tree to retrieve a lost football. If he does 2,400 J of work to climb 8 m, how much force is he using?

krok68 [10]

Work = Force * distance.
d = 8 m
W = 2400 J
F = ???

2400 = 8 * F
F = 2400/8
F = 300 N

6 0

4 years ago

Un automovil de 900 kg toma una curva de radio de 40 m con una rapidez constante de 50 km/h. Cual es la fuerza neta necesaria pa

Llana [10]

Answer:

Fc = 4340,93 Newton

Explanation:

Dados los siguientes datos;

Masa = 900 kg

Velocidad, V = 50 km/h a metros por segundo = (50 * 1000)/(60 * 60) = 50000/3600 = 13,89 m/s

Radio, r = 40 m

Para encontrar la fuerza centrípeta;

Fc = mv² / r

Fc = (900 * 13,89²)/40

Fc = (900 * 192,93)/40

Fc = 173637/40

Fc = 4340,93 Newton

4 0

3 years ago

This tasty snack starts as a kernel and is “popped” then

Veronika [31]

Popcorn can be popped by either of the three forms of heat transfer:

Conduction in a pan with hot oil on a stove element.

Convection by an air popper and warm air rising over a heating element... no direct contact with heat source.

Radiation is what occurs in a microwave. Invisible radiant heat activates water molecules in the popcorn.

All the above heat the kernel over 100 Celsius. Water vaporizes/boils (latent heat) and erupts through the kernel.

Mmmm popcorn watch out for the lipids (fat in the oil and butter)

6 0

3 years ago

A 3.0-kilogram object is acted upon by an impulse having a magnitude of 15 newton•seconds. What is the magnitude of the object’s

Ilia_Sergeevich [38]

The mass of the object doesn't matter. The change in its momentum is equal to the impulse that changed it ... 15 N-sec.

3 0

3 years ago