MATHPHYS HELP
PLS PHYSICS IS MUCH HARDER NOT BEING IN SCHOOL

(001) 4. Heating 100 g of water from 10°C to 50°C

(002) 4.32 km

(003) 5. B only

(004) 347°C

(005) 73.5 °C

(006) 4.9 g

(007) 3. Adding the same amount of heat to two different objects will produce the same increase in temperature.

Explanation:

(001) Heat is the product of mass, specific heat capacity, and temperature change.

q = mCΔT

The specific heat of water is 1 cal/g/°C.  So the heat required for each is:

1. q = (1000 g) (1 cal/g/°C) (12°C − 10°C) = 2000 cal

2. q = (10 g) (1 cal/g/°C) (40°C − 10°C) = 300 cal

3. q = (1 g) (1 cal/g/°C) (80°C − 10°C) = 70 cal

4. q = (100 g) (1 cal/g/°C) (50°C − 10°C) = 4000 cal

(002) A "food Calorie" is 1 kcal = 1000 cal, or 4186 Joules.

Work = change in energy

W = ΔPE

W = mgΔh

758 kcal (4186 J/kcal) = (74.9 kg) (9.8 m/s²) h

h = 4320 m

h = 4.32 km

(003) Heat flows from higher temperature to lower temperature.

It's important to note that an object can have more thermal energy and still have a lower temperature.  For example, the ocean has low temperature but a very large mass, so it has more thermal energy than a cup of coffee, which has higher temperature but a much smaller mass.

(004) Kinetic energy = heat

KE = q

½ mv² = mCΔT

½ v² = CΔT

ΔT = v² / (2C)

ΔT = (298 m/s)² / (2 × 128 J/kg/°C)

ΔT = 347°C

(005) Heat gained by the glass = heat lost by water

m₁C₁ΔT₁ = -m₂C₂ΔT₂

(300 g) (0.2 cal/g/°C) (T − 32°C) = -(199 g) (1 cal/g/°C) (T − 86°C)

(60 cal/°C) (T − 32°C) = -(199 cal/°C) (T − 86°C)

(60 cal/°C) T − 1920 cal = -(199 cal/°C) T + 17114 cal

(259 cal/°C) T = 19034 cal

T = 73.5 °C

(006) Heat gained by ice = heat lost by water

m₁C₁ΔT₁ = m₂L₂

(49 g) (0.5 cal/g/°C) (0°C − (-16°C)) = m (80 cal/g)

392 cal = m (80 cal/g)

m = 4.9 g

(007) Heat is the product of mass, specific heat capacity, and temperature change.

q = mCΔT

So if two objects have different masses, or different heat capacities, then adding the same amount of heat will produce different increases in temperature.

Statement 3 is false.

a women have faced negative attitudes in some areas , but other

because it says use -2,0,and 2 for x, we can plug those numbers into the equation. y/4=3/4(-2)+2   y/4= -1 1/2 +2 now to get x by itself, we can multiply each side by 4. y=-6+8 which equals y=2 when x=-2. now you can do the same thing with 0 and 2 as x. you get y=8 when x=0 and y=14 when x=2.

x   |   y

-2 |   2

0   |   8

2   |   14