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Which expression represents the sum of 8 and twice a number<br> 8+n<br> 8+2n<br> 8×2n<br> 2×(8+n)

Lynna [10]

Answer:

8 + 2 n (second expression listed)

Explanation:

Since we don't know the number, we represent it with a letter (n).

Twice a number (two times that number) will therefore be: 2 n.

and the addition (sum) of 8 to such will lead to 8 + 2 n

The sum of 8 and twice a number is : 8 + 2 n

7 0

3 years ago

A 0.80 kg object tied to the end of a 2.0 m string swings as a pendulum. At the lowest point of its swing, the object has a kine

devlian [24]

Answer:

3.32 m/s

Explanation:

From the law of conservation of energy, the sum of mechanical and kinetic energy should be equal to the 10 J given. Potential energy is given by mgh where m is mass, g is acceleration due to gravity and h is the height. For this case, $h= l(1-cos\theta)$ and l is string length, given as 2 m, \theta is given as 50 degrees. Kinetic energy is given by $0.5mv^{2}$ and it is this velocity that is unknown.

$10J=0.5\times 0.8kg\times v^{2}+ 0.8kg\times 9.81\times 2m(1-cos 50^{\circ})\\v\approx 3.32 m/s$

6 0

4 years ago

A 0.32 kg turntable of radius 0.18 m spins about a vertical axis through its center. A constant rotational acceleration causes t

Kruka [31]

Answer: $18.85 rad/s^2$

Explanation:

Given

mass of turntable $m=0.32 kg$

radius $r=0.18 m$

$N=24 rev/s$

$\omega =2\pi N=2\pi 24$

$\omega =48\pi rad/s$

time interval $t=8 s$

using $\omega =\omeag _0+\alpha t$

where $\omega =final\ angular\ velocity$

$\omega _0=initial\ angular\ velocity$

$\alpha =angular\ acceleration$

$t=time$

$48\pi =0+\alpha \times 8$

$\alpha =6\pi rad/s^2$

$\alpha =18.85 rad/s^2$

5 0

3 years ago

What is the equation to find the volume of a hemisphere? I know the equation to get the volume of a sphere. It's 4/3 pi R cubed?

Tamiku [17]

1/2 x 4/3 pi r cubed = 2/3 pi r cubed

6 0

3 years ago

A golf ball is released from rest from the top of a very tall building. Choose a coordinate system whose origin is at the starti

Zigmanuir [339]

Answer:

Velocity of the ball after 3.04 (s) = 29.79 (m/s)

Explanation:

From the free fall movement we have the following formulas: $Vf^{2} = Vo^{2} - 2gh$ and $h=Vo*t - \frac{g*t^{2} }{2}$ , First we need to find the height to time iqual to 3.04 s using the formula: $h=Vo*t - \frac{g*t^{2} }{2}$ and remember that golf ball was released from the rest (Vo= 0 (m/s)) so $h= (0 (m/s))*(3.04 (s)) - \frac{9.8 (m/s^2)*(3.04 (s))^{2} }{2}$ , we get: h = -45.28 (m) with the height that we have got, now the velocity of the ball is calculate using $Vf^{2} = Vo^{2} - 2gh$ solving for Vf, we get: $Vf = \sqrt{Vo^{2}-2*g*h }$ replacing the values given $Vf = \sqrt{(0 m/s)^{2}-2*(9.8 m/s^2)*(-45.28 m) }$ , so we get: Vf = 29.79 (m/s).

5 0

4 years ago

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