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3 years ago

If we ignore air resistance, a falling body will fall 16t2 feet in t seconds. What is the average velocity between t

Physics

1 answer:

erik [133]3 years ago

7 0

Answer:

262.4 m/s

Explanation:

The complete question is

If we ignore air resistance, a falling body will fall 16t^2 feet in t seconds. What is the average velocity between t=8 and t=8.4? Round your answer to two decimal places if necessary.

The distance fallen s = 16t^2

The velocity v = $\frac{ds}{dt}$ = 32t

If we substitute the values of t into the velocity v, we'll have

at t = 8 s, V1 = 32 x 8 = 256 m/s

at t = 8.4 s, V2 = 32 x 8.4 = 268.8 m/s

Average velocity = (V2 - V1)/2 = (268.8 + 256)/2 = 262.4 m/s

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Which statements about velocity are true?

OleMash [197]

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3 years ago

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Determine whether each of the statements below is true or false, and place it in the appropriate bin. Objects with equal speeds

lisov135 [29]

Objects with equal speeds definitely have equal velocities. -- FALSE. For equal velocities, they also have to be going in the same direction.

If you are given an object's velocity, you can definitely determine its speed. -- TRUE. If you know the velocity, then you know both the object's speed and its direction.

If you know the distance an object travels, and the time it takes to do so, you can determine the object's velocity. -- FALSE. Knowing the distance and time, you can figure out the object's speed. But if you don't also know the direction it's moving, then you can't say what its velocity is.

If an object moves at constant speed, it must also be moving at constant velocity. -- FALSE. Besides constant speed, it also needs to move in a straight line to have constant velocity. If it turns, its velocity changes, even if its speed doesn't.

If an object moves at constant velocity, it must also be moving at constant speed. -- TRUE. Constant velocity means its speed AND its direction are not changing.

Objects with equal velocities definitely have equal speeds. -- TRUE. If their velocities are equal, then their speeds are equal AND they're moving in the same direction.

After laboring through this one, I'm wondering if there can possibly be any more ways to say the same thing.

7 0

3 years ago

The electric field between two parallel plates is uniform, with magnitude 628 N/C. A proton is held stationary at the positive p

aliina [53]

Answer:

Answer is explained in the explanation section below.

Explanation:

Solution:

Data Given:

Electric Field between two parallel plates = 628 N/C

Separation = 4.22 cm

a) In this part, we are asked to calculate the distance from positive plate at which the electron and proton pass each other.

Solution:

First of all:

Force on proton due to the Electric field between the plates is:

$F_{p}$ = $q_{p}$ E

and, we know that, F = ma

So,

$m_{p}$ a = $q_{p}$ E

a = $\frac{q_{p}.E }{m_{p} }$ Equation 1

So,

The distance covered by the electron is:

S = ut + 1/2 $at^{2}$

Here, u = 0.

S = 1/2 $at^{2}$

Put equation 1 into the above equation:

S = 1/2 x ( $\frac{q_{p}.E }{m_{p} }$ ) $t^{2}$ Equation 2

So,

Similarly, the distance covered by electron will be:

(D-S) = 1/2 x ( $\frac{q_{e}.E }{m_{e} }$ ) $t^{2}$ Equation 3

We know that the charge of electron is equal to the charge of proton so,

$q_{p}$ = $q_{e}$ = q

By dividing the equation 2 by equation 3, we get:

$\frac{S}{D-S}$ = $\frac{m_{e} }{m_{p} }$

Solve the above equation for S,

S $m_{p}$ = $m_{e}$ D - $m_{e}$ S

So,

S = $\frac{m_{e}.D }{(m_{e} + m_{p}) }$

Plugging in the values,

As we know the mass of electron is 9.1 x $10^{-31}$ and the mass of proton is 1.67 x $10^{-27}$

S = $\frac{9.1 . 10^{-31} . 4.22 }{(9.1 . 10^{-31} + 1.67 . 10^{-27} }$

S = 0.002298 cm (Distance from the positive plate at which the two pass each other)

b) In this part, we to calculate distance for Sodium ion and chloride ion as above.

So,

we already have the equation, we need to put the values in it.

So,

S = $\frac{m_{Cl}.D }{(m_{Cl} + m_{Na}) }$

As we know the mass of chlorine is 35.5 and of sodium is 23

S = $\frac{35.5 . 4.22}{(35.5 + 23)}$

S = 2.56 cm

7 0

2 years ago

Calculate the minimum amount of work needed to move a 500-kg rocket payload from Earth's surface to the ISS in orbit 400,000m ab

WINSTONCH [101]

Answer:

2.000.000.000

Explanation:

Apply the formula:

Work = Force . Displacement

W = 500.10 . 400.000 (the 10 come from gravity)

W = 5000 . 400.000

W = 2.000.000.000 Joules

I think it is that, can be wrong.

7 0

3 years ago

An oscillator consists of a block of mass 0.628 kg connected to a spring. When set into oscillation with amplitude 27 cm, the os

oksian1 [2.3K]

Answer:

T=0.372 s, f=2.7 Hz, w=16.9 rad/s, k=179.2 N/m, v= 8.78 m/s, F= 48.4 N

Explanation:

a.)

Period: It is already given in the question "oscillator repeats its motion every 0.372 s".

So T=0.372 s

frequency= f = 1/ T

f = 1/ 0.372

f=2.7 Hz

c).

Angular frequency= w= 2πf

w= 2*π*2.7

w=16.9 rad/s

Spring Constant:

As w= $\sqrt{k/m}$

⇒w²= k/m

⇒k= m*w²

⇒k= 0.628 * 16.9² N/m

⇒k=179.2 N/m

The mass will have maximum speed when it passes through the mean position.

At mean position

Maximum elastic potential energy = Maximum kinetic energy

1/2 k A² = 1/2 m v² ( A is amplitude of oscillation)

⇒ v= $\sqrt{k A^2/m}$

⇒ v= $\sqrt{179.2 * 0.27/ 0.628}$ \

⇒ v= 8.78 m/s

Maximum force will be exerted on the block when it is at maximum distance.

F= k* A ( A is amplitude of oscillation)

F= 179.2 * 0.27 N

F= 48.4 N

5 0

3 years ago