Answer:
225 N
Explanation:
"Below the horizontal" means he's pushing down at an angle.
Draw a free body diagram of the box. There are three forces: normal force N pushing up, weight force mg pulling down, and the applied force F at an angle θ.
Sum of forces in the y direction:
∑F = ma
N − mg − F sin θ = 0
N = F sin θ + mg
Plug in values:
N = (50 N) (sin 30°) + (20.0 kg) (10 m/s²)
N = 225 N
Explanation:
This question involves continuous displacement in various directions. When it becomes difficult to imagine, vector analysis becomes handy.
Let us denote each of the individual displacements by a vector. Consider the unit vectors as the unit vectors in the direction of East and North respectively.
By simple calculations, we can derive the unit vectors in the directions North,
South of West and
North of West respectively.
So Total displacement vector = Sum of individual displacement vectors.
Displacement vector =
Magnitude of Displacement =
∴ Total displacement =
This question involves the use of the equations of motion for vertical motion.
The time taken by the stones P and Q to reach the ground is the same, that is "2 s".
The velocity with which Q hits the ground is "20 m/s".
The time taken by the stones to reach the ground can be calculated by using the second equation of motion for the vertical motion:
For both the stones P and Q:
h = height = 20 m
= initial velocity = 0 m/s
t = time = ?
g = acceleration due to gravity = 10 m/s²
Therefore,
<u>t = 2 s</u>
<u></u>
Hence, the time taken by both the stones to reach the ground <u>is the same</u>.
To find the final velocity of stone Q we will use the first equation of motion for the vertical motion:
Learn more about equations of motion here:
brainly.com/question/20594939?referrer=searchResults
The attached picture shows the equations of motion in the horizontal and vertical directions.
