All categories

4 years ago

An example of a substance with a definite volume and a definite shape is

1 answer:

7 0

A. a steel beam. All of the rest of them change shape or volume whereas a steel beam with never change in volume or shape.

You might be interested in

If the kinetic energy of a given mass is to be doubled, its speed must be multiplied by

Tomtit [17]

Answer:

Either B or D. The answer itself is 2.

Explanation:

The equation for the kinetic energy would be 1/2*mv^2.

When m is doubled, we can plug in 1 and 2 to compare our answers.

Plugging in 1 for mass would give us the answer 1/2*v^2.

Plugging in 2 for mass would give us v^2. This means that the velocity was multiplied by 2, meaning that the answer is it is multiplied by 2.

I am not sure which answer is correct since there seems to be two answer choices with 2 in it, but the answer is either B or D (I will call it ABCD because I do not want to cause confusion by saying 2 multiple times).

3 0

3 years ago

What is the speed of an object after falling (from rest) a distance of 9.80 meters near the surface of the Earth? Assume air

madam [21]

Hi there!

We can use the kinematic equation:

$v_f^2 = v_i^2 + 2ad$

vf = Final velocity (? m/s)

vi = initial velocity (0 m/s, dropped from rest)

a = acceleration (due to gravity, 9.8 m/s²)

d = distance (9.8 m)

Simplify the equation to solve for vf:

$v_f^2 = 0 + 2ad\\\\v_f = \sqrt{2ad}$

Substitute in the given values:

$v_f = \sqrt{2(9.8)(9.8)} = \boxed{13.86 m/s}$

8 0

3 years ago

a pendulum, 2.0 m in length, is released with a push when the string is at an angle of 25 o from the vertical. if the initial sp

stiks02 [169]

Answer:

1 / 2 m v^2 = L m g (1 - cos θ)

This is the KE due to the pendulum falling from a 25 deg displacement

v^2 = 2 L g (1 - cos 25) = 2 * 2 * 9.8 (1 - .906) = 3.67 m^2/s^2

v = 1.92 m/s this is the speed due to an initial displacement of 25 deg

Its speed at the bottom would then be

1.92 + 1.2 = 3.12 m/s since it gains 1.92 m/s from its initial displacement

3 0

1 year ago

In just 0.30 s , you compress a spring (spring constant 5000 n/m ), which is initially at its equilibrium length, by 4.0 cm. par

Ierofanga [76]

The average power output is the ratio between the work done to compress the spring, W, and the time taken, t:
$P= \frac{W}{t}$ (1)

The work done is equal to the elastic energy stored by the compressed spring:
$W=U= \frac{1}{2}kx^2$
where $k=5000 N/m$ is the spring constant and $x=4.0 cm=0.04 m$ is the compression of the spring. If we substitute the numbers, we find:
$W= \frac{1}{2}(5000 N/m)(0.04 m)^2=4 J$

And now we can use eq.(1) to calculate the average power output:
$P= \frac{W}{t}= \frac{4 J}{0.30 s} =13.3 W$

7 0

3 years ago

Người ta đúc một khối nhóm (A) và một khối sắt ( (Fe) hình khối với cũng khói lượng 5 kg Khối lượng riêng (2) của Al và Fe là 2

IrinaVladis [17]

Translate to English please

5 0

3 years ago