Answer:
P = 33.6 [N]
Explanation:
To solve this problem we must use Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F = m*a
where:
F = forces [N]
m = mass = 14 [kg]
a = acceleration = 6 [m/s²]
In the second part of this problem we must find the work done, where the work in physics is known as the product of force by distance, it is important to make it clear that force must be applied in the direction of movement.
where:
W = work [J]
F = force = 84 [N]
d = displaciment = 40 [m]
Finally, the power can be calculated by the relationship between the work performed in a given time interval.
where:
P = power [W]
W = work = 3360 [J]
t = time = 100 [s]
Now replacing:
The power is given in watts
Answer:
The distance between the ships is 87.84 km.
Explanation:
Given that,
Angle of first ship= 40°
Speed of first ship = 18 knots
Angle of second ship= 130°
Speed of second ship = 26 knots
We need to calculate the resultant velocity
Using cosine rule
Put the value into the formula
We need to calculate the distance between the ships
Put the value into the formula
Hence, The distance between the ships is 87.84 km.
Answer: N = Mgcos(theta)
Therefore, the Normal reaction force is equal to Mgcos(theta)
Explanation:
See attached for a sketch.
From the attachment.
.
N = normal reaction force on block
W = weight of the block
theta = angle of the inclined plane to the horizontal
From the sketch, we can see that
N is equal in magnitude but opposite direction to Wy
N = Wy
And
Wy = Wcos(theta)
Wx = Wsin(theta)
Then,
N = Wy = Wcos(theta)
But W = mass × acceleration due to gravity = mg
N = Mgcos(theta)
Therefore, the Normal reaction force is equal to Mgcos(theta)
