A 2200 kilogram car is accelerating at 3.4 m/s/s. what is the NET force?

A package rests on the floor of an elevator that is rising with constant speed. the elevator exerts an upward normal force on th

Tomtit [17]

Because the actual package isn't moving so the gravitational potential energy stays the same. kinetic energy is gained through motion of the object not the motion of the surroundings of the object so
unless the package is falling out of a window its losing gravitational potential energy and gaining kinetic energy. hope this helps :-)

6 0

3 years ago

what happens to the specific heat capacity of a material if it changes state? i.e. from solid to liquid

Zigmanuir [339]

Answer:

A solid substance at its melting point has less energy than the same mass of the substance when it is a liquid at the same temperature. ... This heat energy allows the change of state to happen, and the temperature remains constant during the process.

Explanation:

6 0

3 years ago

An aluminum calorimeter with a mass of 100 g contains 250 g of water. The calorimeter and water are in thermal equilibrium at 10

Alexeev081 [22]

Answer:

a) $c=1822.3214\ J.kg^{-1}.K^{-1}$

b) This value of specific heat is close to the specific heat of ice at -40° C and the specific heat of peat (a variety of coal).

c) The material is peat, possibly.

d) The material cannot be ice because ice doesn't exists at a temperature of 100°C.

Explanation:

Given:

mass of aluminium, $m_a=0.1\ kg$

mass of water, $m_w=0.25\ kg$

initial temperature of the system, $T_i=10^{\circ}C$

mass of copper block, $m_c=0.1\ kg$

temperature of copper block, $T_c=50^{\circ}C$

mass of the other block, $m=0.07\ kg$

temperature of the other block, $T=100^{\circ}C$

final equilibrium temperature, $T_f=20^{\circ}C$

We have,

specific heat of aluminium, $c_a=910\ J.kg^{-1}.K^{-1}$

specific heat of copper, $c_c=390\ J.kg^{-1}.K^{-1}$

specific heat of water, $c_w=4186\ J.kg^{-1}.K^{-1}$

Using the heat energy conservation equation.

The heat absorbed by the system of the calorie-meter to reach the final temperature.

$Q_{in}=m_a.c_a.(T_f-T_i)+m_w.c_w.(T_f-T_i)$

$Q_{in}=0.1\times 910\times (20-10)+0.25\times 4186\times (20-10)$

$Q_{in}=11375\ J$

The heat released by the blocks when dipped into water:

$Q_{out}=m_c.c_c.(T_c-T_f)+m.c.(T-T_f)$

where

$c=$ specific heat of the unknown material

For the conservation of energy : $Q_{in}=Q_{out}$

so,

$11375=0.1\times 390\times (50-20)+0.07\times c\times (100-20)$

$c=1822.3214\ J.kg^{-1}.K^{-1}$

b)

This value of specific heat is close to the specific heat of ice at -40° C and the specific heat of peat (a variety of coal).

c)

The material is peat, possibly.

d)

The material cannot be ice because ice doesn't exists at a temperature of 100°C.

7 0

3 years ago

A electric heater that draws 13.5 a of dc current has been left on for 10 min. how many electrons that have passed through the h

kicyunya [14]

By definition, Ampere is a unit of current which is a measure of the amount of charge passing through a point in a circuit per unit of time, with an equivalent charge of 1.602 x 10^(-19) Coulomb per electron. To determine the number of electrons passing through the heater, we use the definition of the current. We calculate as follows:

13.5 A = 13.5 C per second
Charge = 13.5 C/s (10 min) ( 60 s / 1 min)
Charge = 8100 C

Number of electrons = 8100 C / 1.602 x 10^(-19) C per electron
Number of electrons = 5.1 x 10^22 electrons

Therefore, there are 5.1 x10^22 electrons that assed through the heater for 10 minutes.

3 0

3 years ago

What happens when the dew point and the temperature are the same?

Kamila [148]

The value of relative humidity becomes 100% leading to condensation of water vapor in the air into water droplets or water (dew)

4 0

3 years ago