False because the first law of motion is the crash I think I’m in middle school
Answer:
1. 1800 W
2. $ 17.3
Explanation:
From the question given above, the following data were obtained:
Current (I) = 15 A
Voltage (V) = 120 V
Time (t) = 20 h per day
Duration = 31 days
Cost = 15.5 cents per kWh
1. Determination of the power.
Current (I) = 15 A
Voltage (V) = 120 V
Power (P) =?
P = IV
P = 15 × 120
P = 1800 W
Thus, 1800 W of power is required.
2. Determination of the cost per month (31 days).
We'll begin by converting 1800 W to KW.
1000 W = 1 KW
Therefore,
1800 W = 1800 W × 1 KW / 1000 W
1800 W = 1.8 KW
Next, we shall determine the energy consumption for 31 days. This can be obtained as follow:
Power (P) = 1.8 KW
Time (t) = 2 h per day
Time (t) for 31 days = 2 × 31 = 62 h
Energy (E) =?
E = Pt
E = 1.8 × 62
E = 111.6 KWh
Finally, we shall determine the cost of consumption. This can be obtained as follow:
1 KWh = 15.5 cents
Therefore,
111.6 KWh = 111.6 KWh × 15.5 cents / 1 KWh
111.6 KWh = 1729.8 cents
Converting 1729.8 cents to dollar, we have:
100 cents = $ 1
Therefore,
1729.8 cents = 1729.8 cents × $ 1 / 100 cents
1729.8 cents = $ 17.3
Thus, it will cost $ 17.3 per month to run the electric heater.
Answer:
The mass of the block m is:
Explanation:
Let's analyze the block by parts
For the block M
(1)
Where:
- T is the tension
- W(x) is the component of the weight in the x-direction
- F(f) is the friction force
For the block m
(2)
Now, let's combines equation (1) and (2):
Finally, let's solve it for block m.
I hope it helps you!
<h2>
Answer: 26,8 s</h2>
Explanation:
If we are talking about an acceleration at a constant rate , we are dealing with constant acceleration, hence we can use the following equations:
(1)
(2)
Where:
is the final velocity of the plane (the takeoff velocity in this case)
is the initial velocity of the plane (we know it is zero because it starts from rest)
is the constant acceleration of the plane to reach the takeoff velocity
is the distance of the runway
is the time
Knowing this, let's begin with (1):
(3)
(4)
(5)
Substituting (5) in (2):
(6)
Finding
:
This is the time needed to take off