Answer:
F = 9.81 [N]
Explanation:
To solve this problem we must use Newton's third le which tells us that the sum of forces on a body that remains static must be equal to one resulting from these forces in the opposite direction.
Let's perform a summation of forces on the vertical axis-y to determine the normal force N.
∑F = 0 (axis-y)
where:
m = mass = 4 [kg]
g = gravity acceleration = 9.81 [m/s²]
![N - (4*9.81)=0\\N = 39.24 [N]](https://tex.z-dn.net/?f=N%20-%20%284%2A9.81%29%3D0%5C%5CN%20%3D%2039.24%20%5BN%5D)
Now we know that the frictional force can be calculated using the following equation.
f = μ*N
where:
f = friction force [N]
μ = friction coefficient = 0.25
N = normal force = 39.24 [N]
Now replacing:
![f = 0.25*39.24\\f = 9.81[N]](https://tex.z-dn.net/?f=f%20%3D%200.25%2A39.24%5C%5Cf%20%3D%209.81%5BN%5D)
Then we perform a sum of forces on the X-axis equal to zero. This sum of forces allows us to determine the minimum force to be able to move the object in a horizontal direction.
∑F = 0 (axis-x)
![F-f=0\\F-9.81=0\\F= 9.81[N]](https://tex.z-dn.net/?f=F-f%3D0%5C%5CF-9.81%3D0%5C%5CF%3D%209.81%5BN%5D)
If the coefficient was smaller, a smaller force (F) would be needed to start the movement, this can be easily seen by replacing the value of 0.25, by smaller values, such as 0.1 or 0.05.
If the coefficient were larger, a larger force would be needed.
Answer:
1.86 s
Explanation:
Given the expression
h(t) = -16t²+ 64...................... Equation 1
Where h = height of the object, t = time it will take the object to hit the ground.
Given: h = 64 foot.
We have to concert from foot to meters
If 1 foot = 0.3048 meters
Then, 64 foot = 0.3048×64 = 19.51 meters.
We substitute the value of h into equation
119.51 = -16t²+64
-16t² = 199.51-64
-16t² = 55.51
t² = 55.51/-16
t² = 3.469
t = √3.469
t = 1.86 s.
Hence it will take the object 1.86 s to hit the ground.
The best answer is b) <span>Method 1 and Method 3
Method 2, which is part of every other options, does involve using extra water because the dishwasher will necessarily use extra water, even if it is full when you use it.
On the other hand, fixing leaky faucets requires no extra water and the recycled water used to wash your car has already been used. </span>
Complete question is;
Selena drew a diagram to show how current moves in a loop of wire that is placed between two magnets. At top left a piece of magnet labeled N and at top right a piece labeled S. Between these a square coil of wire with green arrows at its ends away from the magnets pointing away from the magnets. Red arrows point from N to S. Which best explains how Selena can correct her error?
A) She can change the magnets so like poles are facing each other.
B) She can change the arrows so they show current traveling in opposite directions on the sides of the loop.
C) She can change the arrows so they show the magnetic field reversing direction between the magnets.
D) She can change the magnetic poles so they are both on one side of the loop.
Answer:
B) She can change the arrows so they show current traveling in opposite directions on the sides of the loop.
Explanation:
Since the direction of the arrows point north and south whereas the magnets are east and west, it means the arrows are not pointing in the correct direction. To correct it she will have to make sure the arrows are pointing in opposite directions of the magnet via the sides of the loop.
Try B if it is not it I am sorry I checked on Google
