For the first one 320
second
1200W
Data
R = 12 Ω ∆V = 120V I =? P =?
Solution:
According to Ohm’s law,
∆V = I R
I = ∆V / R
= 120 / 12
= 10 A
Power P = I ∆V
= 10 x 120
= 1200 W
Third
∆V = 120 V P = 60 W I =? R =?
Use the formula, P = I ∆V
I = P / ∆V = 60 / 120 = 0.5 A
∆V = I R
R = ∆V / I = 120 / 0.5 = 240 Ω
Answer:
4 m/s^2
Explanation:
The acceleration is defined as: Δv/Δt (the difference of the velocity over a time period in which happens that difference).
Remember that a difference is calculated by subtracting the initial value of a physical quantity from its final value.
In our case:
Δv = Vfinal - Vinitial = 36m/s - 0 m/s = 36m/s
Δt = 9s
a = Δv/Δt = 36m/s / 9s = 4m/s^2
Answer: 4
The mechanical advantage is the ratio of the force exerted by the object to the force applied to do work on it.
Here, Jeff tried to lift a rock weighing 600 pounds by wedging board under the rock. Jeff who weighs 150 pounds uses all his weight to exert force on lever and lift rock.
Mechanical advantage, 
Therefore, the mechanical advantage that lever provided to Jeff in lifting rock is 4.
Explanation:
1st- states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction.
2nd- states that the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it. (most important law)
3rd- states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction. (law of action/reaction)
Models help us to understand systems and their properties
