C. Lack of mates. If they cannot reproduce enough, their size will reduce.
If the wagon travels 18.75 m, then the work done on the wagon is
(18.75 m) x (the steady force applied to the wagon all the way, in Newtons) .
The unit is Joules .
Answer:
120 W lightbulb
Explanation:
Let the two lightbulb be A and B respectively.
Given the following data;
Power A = 120W
Power B = 90W
Voltage = 120V
To find the current flowing through each lightbulb;
a. For lightbulb A
Power = current * voltage
120 = current * 120
Current = 120/120
Current = 1 Ampere.
b. For lightbulb B
Current = power/voltage
Current = 90/120
Current = 0.75 Amperes
Therefore, the lightbulb that carries more current is A with 1 Ampere.
Note that
1 J = 0.239 cal
By definition,
Work = Force x Distance
Therefore work done is
W = (1 N)*(2000 m) = 2000 J
In calories,
W = (2000 J)*(0.239 cal/J) = 478 cal
Answer: 478 calories