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3 years ago

Which of the following terms best describes why a skier sliding down a hill eventually comes to a stop?

2 answers:

6 0

Acceleration means you go faster
inertia means it has a tendency to do nothing or remain unchanged
gravity is what pulls things down to earth
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.
so i would say friction

snow_lady [41]3 years ago

5 0

D. Friction because friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. The friction between the two surfaces converts kinetic energy into thermal energy.

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[TRUE/FALSE] If an object is moving at constant velocity it must be in equilibrium.

DENIUS [597]

Answer:

yes

Explanation:

objects with constant velocity also have zero net external force. this means the forces on the object are balanced. this mean they are in equilibrium

4 0

4 years ago

Average velocity is different than average speed because calculating average velocity involves

borishaifa [10]

Answer:

average velocity include total displacement whereas average speed include total distance

6 0

3 years ago

A 40-kg box is being pushed along a horizontal smooth surface. The pushing force is 15 n directed at an angle of 15Â° below the

Kobotan [32]

Answer:

Acceleration of the crate is 0.362 m/s^2.

Explanation:

Given:

Mass of the box, m = 40 kg

Applied force, F = 15 N

Angle at which the force is applied, $(\theta)$ = 15°

We have to find the magnitude of the acceleration.

Let the acceleration be "a".

FBD is attached with where we can see the horizontal and vertical component of force.

⇒ $F_x=Fcos(\theta)$ and ⇒ $F_y=Fsin (\theta)$

⇒ $F_x=15cos(15)$ ⇒ $F_y=15sin (15)$

⇒ Applying concept of forces.

⇒ $\sum F_x=F_n_e_t =F-f$

⇒ $F_n_e_t =F-f$

⇒ $ma =F-f$ ...Newtons second law Fnet = ma

⇒ $a =\frac{F-f}{m}$

⇒ Plugging the values.

⇒ $a =\frac{15cos(15)-0}{40}$ ...f is the friction which is zero here.

⇒ $a =\frac{14.48}{40}$

⇒ $a=0.362\ ms^-^2$

Magnitude of the acceleration of the crate is 0.362 m/s^2.

4 0

3 years ago

If a cell phone is dropped from a very tall building, how far has the phone fallen after 2.7 seconds, neglecting air resistance?

Zielflug [23.3K]

The free fall of the phone is an uniformly accelerated motion toward the ground, with constant acceleration equal to
$g=9.81 m/s^2$

So, assuming the downward direction as positive direction of the motion, since the phone starts from rest the distance covered by the phone after a time t is given by
$y(t) = \frac{1}{2}gt^2$
And if we substitute t=2.7 s, we find the distance covered:
$y(t)= \frac{1}{2}(9.81 m/s^2)(2.7 s)^2=35.8 m$

6 0

3 years ago

Please help me with this question

Alexandra [31]

Answer:

(4) A = 3 A, A₂ = 11 A

(5) 7 A

Explanation:

(4)

From the diagram,

A = 3+6+2

A = 11 A

V = A₂R

A₂ = V/R₂............ Equation 1

Given: V = 12 V, R₂ = 4 Ω

Substitute these values into equation 1

A₂ = 12/4

A₂ = 3 A

(5) Applying,

V = IR'

I = V/R'............ Equation 1

Where V = Voltage, I = cuurent, R' = total resistance.

But,

1/R' = (1/3)+(1/4)

1/R' = (3+4)/12

1/R' = 7/12

R' = 12/7 Ω

Given: V = 12 V

Substitute these values into equation 1

I = 12/(12/7)

I = 7 A

Therefore

A = 7 A

5 0

3 years ago