Answer:
45.2
Step-by-step explanation:
Explanation:
The idea here is that you need to use the mass of water, the heat added to the sample, and the specific heat of water to find the resulting change in temperature.
The equation that establishes a relationship between heat absorbed and change in temperature looks like this
q
=
m
⋅
c
⋅
Δ
T
, where
q
- heat absorbed
m
- the mass of the sample
c
- the specific heat of water, equal to
4.18
J
g
∘
C
Δ
T
- the change in temperature, defined as final temperature minus initial temperature
Plug in your values and solve for
Δ
T
- do not forget to convert the added heat from kilojoules to Joules
q
=
m
⋅
c
⋅
Δ
T
⇒
Δ
T
=
q
m
⋅
c
Δ
T
=
1.0
⋅
10
3
J
50.0
g
⋅
4.18
J
g
∘
C
=
4.785
∘
C
So, if the temperature of the water changed by
4.785
∘
C
, and its final temperature is now
50.0
∘
C
, it follows that its initial temperature was
Δ
T
=
T
f
−
T
i
⇒
T
i
=
T
f
−
Δ
T
T
i
=
50.0
∘
C
−
4.785
∘
C
=
45.2
∘
C
Answer:
1. 600 watts
2. 35640 J
3. 55%
4. 20 J
5. The cost of running the fire is 8p.
Step-by-step explanation:
1. Energy = 36 000 J , t = 1 minute = 60 seconds
Power =
=
= 600 watts
2. Power =
⇒ work done = Power × time
= 99 × 360
= 35640 J
3. Efficiency = (Output / Input) × 100
= × 100
= 55%
4. Work done = Force × distance
= 5 × 4
= 20 J
5. Given that 1 KWh cost 2p, Power = 4 KW and time = 4 hours.
Power =
Energy = Power × time
= 4 × 4
= 16 KWh
The cost of running the fire =
= 8p
If you were to think of this diagram as a map of intersecting roads, corresponding angles are the ones on the same corner:
NW corner: ∠1 and ∠3
NE corner: ∠5 and ∠7
SE corner: ∠6 and ∠8
SW corner: ∠2 and ∠4
The choices in bold font above are the only pairs of corresponding angles that are in your answer list:
- ∠1 and ∠3
- ∠5 and ∠7
- ∠6 and ∠8
I believe it would be D. Hope that helped;)
Answer:
64
Step-by-step explanation:
=> 8²
=> 8 × 8
=> 64