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3 years ago

A force acting on an object does no work if

2 answers:

8 0

If the force is not in the direction of the object’s motion then a <span> force acting on an object does no work
work is done if force is applied on a body and body covers some distance in the direction of the force
W=FS
hope it helps</span>

KIM [24]3 years ago

3 0

Answer: the force is not in the direction of the object’s motion.

Explanation:

Work = Force. Displacement

⇒ W = F. s = F s cos θ

Thus, work is said to be done when a force displaces an object from its position in the direction of the force.

If the force is less the frictional force, the object would not move. An object accelerates when a force is applied. Sometimes, the direction of force and direction of motion is not same. In that case, no work is said to be done.

For example, when porter lifts the weight on head and moves forward. The weight is perpendicular to the direction of motion. cos 90° = 0 ⇒ W = 0

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Describing the Changes in the Ator Based on the article "Will the real atomic model please stand up?,"describe one major change

andrew11 [14]

Answer: the last period. i think has the largest energy level

Explanation:

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3 years ago

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An electron in a TV picture tube is accelerated through a potential difference of 10 kV before it hits the screen. What is the k

laiz [17]

Answer:

10,000 eV

Explanation:

According to the law of conservation of energy, the kinetic energy gained by the electron is equal to its change in electric potential energy:

$K=\Delta U=q \Delta V$

where:

K is the kinetic energy of the electron

$q=1 e$ is the magnitude of the charge of the electron

$\Delta V$ is the potential difference through which the electron has been accelerated

For this electron in the TV, we have

$\Delta V=10 kV=10000 V$

Therefore, the kinetic energy of the electron in electronvolts is

$K=(1 e)(10000 V)=10000 eV$

7 0

4 years ago

A block of weight 1200N is on an incline plane of 30° with the horizontal, a force P is applied to the body parallel to the plan

pshichka [43]

Answer:

a) P = 807.85 N, b) P = 392.15 N, c) P = 444.12 N

Explanation:

For this exercise, let's use Newton's second law, let's set a reference frame with the x-axis parallel to the plane and the direction rising as positive, and the y-axis perpendicular to the plane.

Let's use trigonometry to break down the weight

sin θ = Wₓ / W

cos θ = W_y / W

Wₓ = W sin θ

W_y = W cos θ

Wₓ = 1200 sin 30 = 600 N

W_y = 1200 cos 30 = 1039.23 N

Y axis

N- W_y = 0

N = W_y = 1039.23 N

Remember that the friction force always opposes the movement

a) in this case, the system will begin to move upwards, which is why friction is static

P -Wₓ -fr = 0

P = Wₓ + fr

as the system is moving the friction coefficient is dynamic

fr = μ N

fr = 0.20 1039.23

fr = 207.85 N

we substitute

P = 600+ 207.85

P = 807.85 N

b) to avoid downward movement implies that the system is stopped, therefore the friction coefficient is static

P + fr -Wx = 0

fr = μ N

fr = 0.20 1039.23

fr = 207.85 N

we substitute

P = Wₓ -fr

P = 600 - 207,846

P = 392.15 N

c) as the movement is continuous, the friction coefficient is dynamic

P - Wₓ + fr = 0

P = Wₓ - fr

fr = 0.15 1039.23

fr = 155.88 N

P = 600 - 155.88

P = 444.12 N

6 0

3 years ago

Which wave form oscillates both parallel and perpendicular to the direction of the wave motion? transverse waves, longitudinal w

Solnce55 [7]

Hope this answer helps:)

6 0

3 years ago

If a town was 90 miles away and you travel at 45 mph how long would it take to get there

notka56 [123]

Answer:

t = 2 hours

Explanation:

Given that,

Distance of the town, d = 90 miles

Speed, v = 45 mph

We need to find the time to get there. The speed of an object is given by :

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

Where

t is time

$t=\dfrac{d}{v}\\\\t=\dfrac{90}{45}\\\\t=2\ h$

So, the required time is 2 hours.

5 0

3 years ago