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2 years ago

14

If I have an object that starts from rest and reaches a velocity of 25m/s over a distance of 11m what is the acceleration of the

object
28.4m/s
28m/s
28.4m/s^2
28m/s^2

1 answer:

Elodia [21]2 years ago

3 0

Answer:

Here is something that may help you!!

Explanation:

I found it in a cite (not that I'm plagiarizing, or anything).

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A ramp is used to load furniture onto a moving truck. The person does 1240 J of work pushing

Len [333]

Answer:

The efficiency of the ramp is, Eff = 6.63 %

Explanation:

Given,

The work done by the person pushing the furniture up the ramp is, W₁ = 1240 J

The work done by the ramp is, W₀ = 822 J

The efficiency of the ramp is given by the formula,

<em> Eff = ( W₀ / W₁ ) x 100%</em>

= ( 822 / 12400 ) x 100%

= 6.63 %

Hence, the efficiency of the ramp is, Eff = 6.63 %

6 0

3 years ago

Children are sled riding on a hill One little girl pulls her sled back up the hill and does 379.5 joules of work while pulling i

Serggg [28]

Answer:

2.2N

Explanation:

Given parameters:

Work done = 379.5J

Height = 173m

Unknown:

Amount of force exerted on the sled = ?

Solution:

The amount of force she exerted on the sled is the same as her weight.

Work done is the force applied to move a body through a distance.

Work done = mgh

m is the mass

g is the acceleration due to gravity

h is the height

mg = weight;

Work done = weight x h

379.5 = weight x 173

weight = $\frac{379.5}{173}$ = 2.2N

4 0

2 years ago

Jet aircraft maintenance crews are required to wear protective earplugs. Members of a particular crew wear earplugs that reduce

Taya2010 [7]

Answer:

So the sound intensity level they would experience without the earplugs is 110.32dB.

Explanation:

Given data

Sound intensity by factor =215

Sound intensity level =87 dB

To find

Sound intensity level they would experience without the earplugs

Solution

First we need to find the new sound intensity level

So

$I_{n}=215(10^{\frac{87}{10} } )\\I_{n}=1.08*10^{11})$

The dB can be calculated as:

$dB=10log(I_{n})\\$

Substitute the given values

$dB=10log(1.08*10^{11})\\dB=110.32dB$

So the sound intensity level they would experience without the earplugs is 110.32dB.

7 0

3 years ago

A small but measurable current of 3.8 × 10-10 A exists in a copper wire whose diameter is 2.5 mm. The number of charge carriers

Karolina [17]

Answer:

a) 4.9*10^-6

b) 5.71*10^-15

Explanation:

Given

current, I = 3.8*10^-10A

Diameter, D = 2.5mm

n = 8.49*10^28

The equation for current density and speed drift is

J = I/A = (ne) Vd

A = πD²/4

A = π*0.0025²/4

A = π*6.25*10^-6/4

A = 4.9*10^-6

Now,

J = I/A

J = 3.8*10^-10/4.9*10^-6

J = 7.76*10^-5

Electron drift speed is

J = (ne) Vd

Vd = J/(ne)

Vd = 7.76*10^-5/(8.49*10^28)*(1.60*10^-19)

Vd = 7.76*10^-5/1.3584*10^10

Vd = 5.71*10^-15

Therefore, the current density and speed drift are 4.9*10^-6

And 5.71*10^-15 respectively

3 0

3 years ago

An electron of mass 9.11x10^-31 kg has an initial speed of 2.40x10^5 m/s. It travels in a straight line, and its speed increases

egoroff_w [7]

Answer: A) Force = 3.841*10^-18 N.

B) force (f) is 4.30* 10^12 times greater than the weight (Fg).

Explanation: mass of electronic charge = 9.11*10^-31kg

v = final velocity = 6.80*10^5 m/s

u = initial velocity = 2.40 * 10^5 m/s

S= distance covered = 4.8cm = 0.048m

a = acceleration

Since the acceleration of the electron is assumed to be constant, newton's laws of motion are valid.

Thus, recall that

v² = u² + 2aS

(6.80*10^5)² = ( 2.40*10^5)² + 2*a( 0.048)

46.24 * 10^10 = 5.76 * 10^10 + 0.096a

46.24 *10^10 - 5.76* 10^10 = 0.096a

40.48* 10^10 = 0.096a

a = 40.48 * 10^10/0.096

a = 4.2167*10^12m/s².

Force = mass * acceleration

Force = 9.11*10^-31 * 4.2167*10^12

Force = 3.841*10^-18 N.

Weight =Fg= mg where g = acceleration due gravity = 9.8m/s²

Fg= 9.11*10^-31 * 9.8

Fg = 8.9278* 10^-30 N

By comparing the force and the weight, we have that

F/Fg = 3.841 * 10^-18/8.9278 * 10^-30 = 4.30* 10^12.

This implies that the force (f) is 4.30* 10^12 times greater than the weight (Fg).

7 0

3 years ago