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2 years ago

A speed-time graph is shown below:

Physics

1 answer:

alexandr1967 [171]2 years ago

3 0

Answer:

<em>The average acceleration of the object is 0.5 cm/s^2</em>. Answer: A)

Explanation:

<u>Average Acceleration</u>

The average acceleration of a moving object is the rate at which the speed changed over time in a specific period. It can be calculated as follows:

$\displaystyle \bar a=\frac{v_f-v_o}{t}$

Where vf is the final speed, vo is the initial speed and t is the time.

The speed-time shows the speed starts at 0 cm/s and ends at 4 cm/s over the 8 seconds period. The average acceleration is:

$\displaystyle \bar a=\frac{4-0}{8}=0.5$

The average acceleration is 0.5 cm/s^2

A) Correct. The average acceleration is 0.5 cm/s^2

B) Incorrect. The average acceleration is 0.5 cm/s^2

C) Incorrect. The average acceleration is 0.5 cm/s^2

D) Incorrect. The average acceleration is 0.5 cm/s^2

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A spacecraft is separated into two parts by detonating the explosive bolts that hold them together. The masses of the parts are

nordsb [41]

Answer:

0.279 m/s

Explanation:

mass (m1) = 1150 kg

mass (m2) = 1900 kg

impulse (J) = 200 N.s

With what relative speed do the two parts separate because of the detonation?

since both parts separate, their relative speed = speed of m1 + speed of m2

speed of m1 = $\frac{J}{m}$ = $\frac{200}{1150}$ = 0.174 m/s

speed of m2 = $\frac{J}{m}$ = $\frac{200}{1900}$ = 0.105 m/s
relative speed = 0.174 + 0.105 = 0.279 m/s

6 0

2 years ago

I need help please and thanks

SCORPION-xisa [38]

Answer:

4.Given:

m=1000kg

a=(3m/s)^2

F=m×a

=1000×3

=3000N

5.Given:

m=50kg

a=(5m/s)^2

F=m×a

=50×5

=250N

6. Given

F=250N

a=(5m/s)^2

m=?

F=m×a

250N=m×(5m/s)^2

m×(5m/s)^2=250N

m=250N÷(5m/s)^2

m=50kg

8 0

3 years ago

On the moon, the gravitational acceleration is approximately one-sixth that on the surface of the earth. A 5-kg mass is "weighed

Rudiy27

Answer:

A. 8.175 N

B. 49.05 N

Explanation:

Acceleration due to gravity (moon) = 1/6 * (acceleration due to gravity (earth)

Acceleration due to gravity (earth) = 9.81 m/s2

Acceleration due to gravity (moon) = 9.81/6

= 1.635 m/s

Weight. Fm = acceleration due to gravity * mass

= 1.635 * 5

= 8.175 N

B. Acceleration due to gravity (earth) * mass = Fe

= 9.81 * 5

= 49.05 N

7 0

2 years ago

Suppose that a parallel-plate capacitor has a dielectric that breaks down if the electric field exceeds K V/m. Thus, the maximum

wel

Answer:

The least possible volume is $2.206*10^{-5} m^3$

Explanation:

We are asked by the least volume to store 1 mJ at 2000 V.

So, we can use the given formula for $W_{max}$ and solve for Vol.

$W_{max} = \frac{1}{2}\epsilon_r \epsilon_0 K^2 Vol\\Vol= 2W_{max}/(\epsilon_r \epsilon_0 K^2)$

replacing the values given in the problem and the permittivity of space $\epsilon_0$ which is $8.854*10^{-12}F/m$ we obtain Vol.

$Vol= 2*0.001 J/(1*8.854*10^{-12}F/m*(32*10^5V/m)^2)\\Vol= 0.002 J/( 90.66496F*V^2/m^3)\\Vol = 2.206*10^{-5} m^3$

Note that $FV^2= J$ in the above solution

Additional:

Taking into account that the volume of dieletric will be the area of plates (A) times the separation between plates (d).

$Vol=A*d$

You also can calculate A and d

d is calculated assuming that the $V_{max}$ is 2000 V and using given equation for $V_{max}$ :

$d= V_{max}/K\\d= 2000V/(32*10^5V/m)\\d=6.25*10^-4 m$

and A is calculated dividing Vol by d

$A= Vol/d=2.206*10^{-5} m^3/6.25*10^-4 m =0.0353 m^2$

3 0

3 years ago

The magnetic field of the brain has been measured to be approximately 3.0×10−12T. Although the currents that cause this field ar

saw5 [17]

Answer:

I = 3.82 x 10^(−7) A

Explanation:

The formula for magnetic field at the centre of a loop is given as;

B = μI/2R

Where μ is a magnetic constant with a value of 12.57 × 10^(−7) H/m.

I = current

R = Radius = 16/2 = 8cm or 0.08m

B = 3.0×10^(−12) T

So making I the subject of the formula, we obtain ;

I = 2RB/μ

Thus, I = [2 x 0.08 x 3.0×10^(−12)]/12.57 × 10^(−7)

I = 3.82 x 10^(−7) A

7 0

2 years ago