Part C

Newton’s Second Law of motion defines force in terms of mass and acceleration, F= ma. Which of the following is false? The term

NikAS [45]

Answer:

The forces creating the net force must lie in the same direction.

Explanation:

newton's second law states that the net force acting on the body is equal to the product of mass and the acceleration of the body.

If there are several forces acting on the body in different directions, then we have to find teh net force by using the vector sum and then find the acceleration.

It is not necessary that all the forces acting in the same direction.

if they are in different directions then we have to find the net force by t=using the formula for the vector sum.

5 0

3 years ago

A very long train is rolling at 4 m/s along a straight track. An observer is standing on the ground very dangerously close to th

hichkok12 [17]

Answer:

A. $\vec{r}=(6\frac{m}{s})t\ \ \hat{i}$

B. t = 50 s

Explanation:

A. The vectorial equation of the person who is getting closer to the other person is:

$\vec{r}=\vec{v}t$

r: position vector

v: speed vector = 6m/s i (if you consider the motion as a horizontal motion)

Then, you replace and obtain:

$\vec{r}=(6\frac{m}{s})t\ \ \hat{i}$

B. The time is:

$t=\frac{d}{v}$

d: distance to the observer = 300m

v: speed of the person on the car = 6.00 m/s

$t=\frac{300m}{6m/s}=50s$

4 0

3 years ago

Which of the following is fact-based science rather than part of a personal belief system?

marusya05 [52]

Since there are no choices, then this question calls for open-ended answers. Facts-based science must have proven underlying laws that support inferences such as Coulomb's Law, Kinetic Theory of Matter and many more. On the other hand, examples of science that focus on personal belief is philosophy. This depends on the perspective of known philosophers. An example would be Sigmund Freud who proposed the theory of 3 personalities. Although it is more on personal beliefs, this is used as a foundation in the study of psychology.

3 0

3 years ago

HELP ME HOW ARE BLACK HOLES FROMED

V125BC [204]

Answer:

Stellar black holes form when the center of a very massive star collapses in upon itself.

6 0

3 years ago

Read 2 more answers

A 15 kg box is sliding down an incline of 35 degrees. The incline has a coefficient of friction of 0.25. If the box starts at re

valina [46]

The box has 3 forces acting on it:

• its own weight (magnitude w, pointing downward)

• the normal force of the incline on the box (mag. n, pointing upward perpendicular to the incline)

• friction (mag. f, opposing the box's slide down the incline and parallel to the incline)

Decompose each force into components acting parallel or perpendicular to the incline. (Consult the attached free body diagram.) The normal and friction forces are ready to be used, so that just leaves the weight. If we take the direction in which the box is sliding to be the positive parallel direction, then by Newton's second law, we have

• net parallel force:

∑ F = -f + w sin(35°) = m a

• net perpendicular force:

∑ F = n - w cos(35°) = 0

Solve the net perpendicular force equation for the normal force:

n = w cos(35°)

n = (15 kg) (9.8 m/s²) cos(35°)

n ≈ 120 N

Solve for the mag. of friction:

f = µ n

f = 0.25 (120 N)

f ≈ 30 N

Solve the net parallel force equation for the acceleration:

-30 N + (15 kg) (9.8 m/s²) sin(35°) = (15 kg) a

a ≈ (54.3157 N) / (15 kg)

a ≈ 3.6 m/s²

Now solve for the block's speed v given that it starts at rest, with v₀ = 0, and slides down the incline a distance of ∆x = 3 m:

v² - v₀² = 2 a ∆x

v² = 2 (3.6 m/s²) (3 m)

v = √(21.7263 m²/s²)

v ≈ 4.7 m/s

4 0

3 years ago