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3 years ago

What if m1 is initially moving at 3.4 m/s while m2 is initially at rest? (a) find the maximum spring compression in this case?

1 answer:

7 0

Ans : Initial E = KE = Â˝mvÂ˛ = Â˝ * 1.2kg * (2.2m/s)Â˛ = 2.9 J max spring compression where both velocities are the same: conserve momentum: 1.2kg * 2.2m/s = (1.2 + 3.2)kg * v â†’ v = 0.6 m/s which means the combined KE = Â˝ * (1.2 + 3.2)kg * (0.6m/s)Â˛ = 0.79 J The remaining energy went into the spring: U = (2.9 - 0.79) J = 2.1 J = Â˝kxÂ˛ = Â˝ * 554N/m * xÂ˛ x = 0.0076 m â† (a)

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A wheel has a constant angular acceleration of 1.8 rad/s2. During a certain 4.0 s interval, it turns through an angle of 45 rad.

tankabanditka [31]

Answer:

4.25 s

Explanation:

Given:

angular acceleration'α'= 1.8 rad/s²

angle 'θ'= 45 rad

time 't'= 4s

initial angular velocity ' $w_{o}$ '=0 $rad^{-1}$

as we know that,

θ= $w_{1}$ t + $\frac{1}{2} \alpha t^{2}$

45 = 4 $w_{1}$ + (0.5 x 1.8 x 16)

45- 14.4 = 4 $w_{1}$

30.6 = 4 $w_{1}$

$w_{1}$ = 7.65 $rad^{-1}$

Next is to find t by using the equation

$w_{1}$ = $w_{o}$ + $\alpha t_{1}$

7.65= 0 + (1.8) $t_{1}$

$t_{1}$ = 7.65/1.8

$t_{1}$ = 4.25 s

Therefore, At the start of 4s interval the motion is at 4.25 second

7 0

3 years ago

Ou drag your feet on a carpeted floor on a dry day and the carpet acquires a net positive charge. a. Will you have an electron d

11Alexandr11 [23.1K]

Answer:

1) We will have excess of electrons

2) The number of electrons transferred equals $1.343\times 10^{10}$

Explanation:

Part a)

Since we know that the charge transfer occurs by the transfer of electrons only as it is given that the carpet has acquired a positive charge it means that it has lost some of the electron's since electrons are negatively charged and if a neutral body looses negative charge it will become positively charged. The electron's that are lost by the carpet will be acquired by the feet of the human thus making us negatively charged.Hence we will gain electrons making us excess in electrons.

Part b)

From charge quantinization principle we have

$Q=ne$

where

Q = charge of body

n = no of electrons

e = fundamental charge

Applying values in the above equation we get

$2.15\times 10^{-9}C=n\times 1.6\times 10^{-19}C\\\\\therefore n=\frac{2.15\times 10^{-9}C}{1.6\times 10^{-19}C}=1.343\times 10^{10}$

4 0

3 years ago

Some kids are playing by rolling a skateboard across level ground beside a 0.75 m high wall. The goal is to drop from the wall v

lys-0071 [83]

Answer:

The speed of the kid and the skateboard together is 0.723 m/s

Explanation:

Let the mass of the kid be $m_{k} = 45 kg$

Let the mass of the skateboard be $m_{s} = 4,5 kg$

The initial speed of the skateboard, $v_{s} = 8 m/s$

The initial horizontal speed of the boy as he jumps on the skateboard, $v_{k} = 0 m/s$

Let the speed of the kid and the skateboard together be v

According to the principle of conservation of momentum:

$m_{k} v_{k} + m_{s} v_{s} = (m_{k} + m_{s}) v$

Substituting the appropriate values into the given equation

$(45*0) + (4.5*8) = (45 + 4.8) v$

36 = 49.8 v

v = 36/49.8

v = 0.723 m/s

7 0

4 years ago

How can electric shock be prevented?

Nina [5.8K]

Wearing rubber or stay away from water or/ and a conductor

7 0

3 years ago

Can someone help me out?

Sphinxa [80]

Answer:

1) The car is slowing down

2) A = 40N forward & B = 25N up

Explanation:

Whenever you're dealing with forces on moving objects, it is important to look at each of the numbers and the directions they're going in.

With the racecar, we see it has four forces on it, 2,000 N up and down, 8,000 back, and 6,000 N forward. Now, each of these forces are going in their respective directions, but they are most in comparison with the force going in the opposite direction (vertical axis, horizontal axis). The two 2,000 N forces will cancel each other out since there is an equal force in both directions, causing a net force of 0 N on the vertical axis. This is because the car is most likely moving on a flat surface. As for the horizontal axis, we simply subtract 6,000 & 8,000 to get a net force of -2,000 N in the backwards direction, telling us that the car is slowing down.

As for the boxes, we see the same vertical and horizontal axes, but separated to each box. Box A has a net force of 40 N in the forward direction and Box B has a net force of 25 N in the upward direction.

4 0

3 years ago