Topic 1 review - heating processes

An iron bar is held with one end in a fire. The other end soon becomes too hot to hold. hand
iron bar How has the heat travelled along the iron bar? 

•  by conduction
• by convection
• by expansion
• by radiation fire 

The diagram shows a cooling unit in a refrigerator. Why is the cooling unit placed at the top? 

• Cold air falls and warm air is displaced upwards.
• Cold air is a bad conductor so heat is not conducted into the refrigerator.
• Cold air is a good conductor so heat is conducted out of the refrigerator.
• Cold air stops at the top and so prevents convection. 

How does heat from the Sun reach the Earth?

• conduction only
• convection only
• radiation only 
• conduction, convection and radiation

Spoons made of different materials were placed in four cups of coffee poured from the same jug. Which spoon will be hottest to touch at end X? 

• A
• B
• C
• D

What is the formula to calculate heat energy required to raise the temperature of any substance?

• Q = mc∆T

• Q = mcT

• Q = ½ mv

• m = Qc

There are four cups of hot cocoa. The cup sizes are shown. The temperature of the cocoa in each cup is 25 degrees celsius. Which cup has the MOST thermal energy?

• Large cup (Trenta)
• Small cup (Tall)
• Venti
• All three are the same temperature so they have same thermal energy

Tags

NGSS.HS-PS3-4

If the specific heat of water is 4,186 J/kg∙°C, how much heat is required to increase the temperature of 1.2 kg of water from 23 °C to 39 °C? 

• -80,371.2 J
• 44,938.6 J
• 80,371.2 J
• 112,575.9 K

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

What would be the effect on the particles if more heat is supplied to the system?

• They would slow down
• They would stop moving
• They would speed up
• There would be no effect

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A sample of iron receives 50.J of heat energy that raises the temperature of the iron 25.0°C. If iron has a specific heat of 0.10 J/g°C, what is the mass of the iron sample?

• 25 g

• 30 g

• 20 g

• 50 g

The specific heat is the amount of energy needed to raise the temperature one degree Celsius of 1 gram of a substance.

• True
• False

Tags

NGSS.HS-PS3-4