The answer is C) the density of the rock
Density of rock is the dependent variable, because it depends on the temperature. The temperature can’t be the dependent variable because ,the density of a rock does not have magical powers that can change temperature of a room. However changing the temperature of the room ,will change the density of the rock. Hope this helps !
Answer : Cat will reach tree first.
Explanation :
It is given that,
Total distance between dog and tree is 30 yards. The cat has 10 yards lead. So, the distance between cat and tree is 20 yards.
Speed of cat is 6 Yards/ sec.
Speed of dog is 8 Yards/sec.
speed of cat is, 


Now, speed of dog is, 


It is clear that, cat is taking less time as compared with dog. So, the cat will reach tree first.
Answer: 3 Amperes
Explanation:
Voltage of battery = 24 volts
R1 = 3Ω
R2 = 5Ω
Total resistance = ?
Current, I = ?
Since the resistors are connected in series, the total resistance (Rtotal) of the circuit is the sum of each resistance.
i.e Rtotal = R1 + R2
Rtotal = 3Ω + 5Ω = 8Ω
Now recall that voltage = current x resistance
i.e V = I x Rtotal
24volts = I x 8Ω
I = 24 volts / 8Ω
I = 3 amperes
Thus, there is 3 Amperes of current in the circuit