Answer:
a) 16 N
b) 2.13 m/s²
Explanation:
Draw a free body diagram of the tv stand. There are four forces:
Weight force mg pulling down,
Normal force N pushing up,
Friction force Nμ pushing left,
and applied force P pulling right.
Sum of forces in the y direction:
∑F = ma
N − mg = 0
N = mg
The net force in the x direction is:
∑F = P − Nμ
∑F = P − mgμ
∑F = 25 N − (7.5 kg) (10 m/s²) (0.12)
∑F = 16 N
Net force equals mass times acceleration:
∑F = ma
16 N = (7.5 kg) a
a = 2.13 m/s²
- Magnitude: 12.1 N.
- Direction: 17.0° to the 8 N force.
<h3>Explanation</h3>
Refer to the diagram attached (created with GeoGebra). Consider the 5 N force in two directions: parallel to the 8 N force and normal to the 8 N force.
.
.
The sum of forces on each direction will be the resultant force on that direction:
- Resultant force parallel to the 8 N force:
. - Resultant force normal to the 8 N force:
.
Apply the Pythagorean Theorem to find the magnitude of the resultant force.
(3 sig. fig.).
The size of the angle between the resultant force and the 8 N force can be found from the tangent value of the angle. Tangent of the angle:
.
Find the size of the angle using inverse tangent:
.
In other words, the resultant force is 17.0° relative to the 8 N force.
What object do you need to match
a) KE=0.5*mv^2==0.5*145*25^2=45312.5 J
b) PE=mgh=145*9.8*3.5=4973.5 J
c) ME=KE+PE=m(0.5v^2+gh)=62524 J
Answer:
b
Explanation:
Brownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules. ... Brownian motion takes its name from the Scottish botanist Robert Brown, who observed pollen grains moving randomly in water. He described the motion in 1827 but was unable to explain it.