All categories

3 years ago

We can see our face clearly on mirror why cant we see our face clear on aluminium or irion plate

Physics

1 answer:

Alexxandr [17]3 years ago

3 0

Explanation:

this is due to the roughness of the metal like you mentioned aluminum and iron are rough and don't provide a reflective surface as good as a mirror

You might be interested in

The main difference between speed and velocity involves

AysviL [449]

Direction. Velocity is a vector that describes both speed and direction, while speed is a scalar that describes only speed regardless of direction.

4 0

3 years ago

What are earths two internal sources of heat energy?

CaHeK987 [17]

the radiogenic heat produced by the radioactive decay of isotopes in the mantle and crust, and the primordial heat left over from the formation of the Earth.

3 0

3 years ago

Two forces are acting on a wheelbarrow. One force is pushing to the right and an equal force is pushing to the left. What can yo

andreev551 [17]

-- As far as we know, the forces on the wheelbarrow are balanced.

-- That tells us that the net force on the wheelbarrow is zero, just
as if there were no forces acting on it at all.

-- That tells us that the wheelbarrow's acceleration is zero ... its
speed and direction of motion are not changing.

-- That tells us that the wheelbarrow is moving in a straight line
at a constant speed. It's very possible that relative to us, the speed
may be zero, but we can't tell that from the given information.

6 0

3 years ago

3.A bridge usually has expansion joints. They allow the bridge to become slightly longer when it

Dominik [7]

Answer:

a) When the sides of the joint are close together, the particles have more kinetic energy than they do when sides are farther apart.

Explanation:

5 0

3 years ago

A merry-go-round of radius R, shown in the figure, is rotating at constant angular speed. The friction in its bearings is so sma

mel-nik [20]

The angular speed of the merry-go-round reduced more as the sandbag is

placed further from the axis than increasing the mass of the sandbag.

The rank from largest to smallest angular speed is presented as follows;

[m = 10 kg, r = 0.25·R]

${}$ ⇩

[m = 20 kg, r = 0.25·R]

${}$ ⇩

[m = 10 kg, r = 0.5·R]

${}$ ⇩

[m = 10 kg, r = 0.5·R] = [m = 40 kg, r = 0.25·R]

${}$ ⇩

[m = 10 kg, r = 1.0·R]

Reasons:

The given combination in the question as obtained from a similar question online are;

1: m = 20 kg, r = 0.25·R

2: m = 10 kg, r = 1.0·R

3: m = 10 kg, r = 0.25·R

4: m = 15 kg, r = 0.75·R

5: m = 10 kg, r = 0.5·R

6: m = 40 kg, r = 0.25·R

According to the principle of conservation of angular momentum, we have;

$I_i \cdot \omega _i = I_f \cdot \omega _f$

The moment of inertia of the merry-go-round, $I_m$ = 0.5·M·R²

Moment of inertia of the sandbag = m·r²

Therefore;

0.5·M·R²· $\omega _i$ = (0.5·M·R² + m·r²)· $\omega _f$

Given that 0.5·M·R²· $\omega _i$ is constant, as the value of m·r² increases, the value of $\omega _f$ decreases.

The values of m·r² for each combination are;

Combination 1: m = 20 kg, r = 0.25·R; m·r² = 1.25·R²

Combination 2: m = 10 kg, r = 1.0·R; m·r² = 10·R²

Combination 3: m = 10 kg, r = 0.25·R; m·r² = 0.625·R²

Combination 4: m = 15 kg, r = 0.75·R; m·r² = 8.4375·R²

Combination 5: m = 10 kg, r = 0.5·R; m·r² = 2.5·R²

Combination 6: m = 40 kg, r = 0.25·R; m·r² = 2.5·R²

Therefore, the rank from largest to smallest angular speed is as follows;

Combination 3 > Combination 1 > Combination 5 = Combination 6 >

Combination 2

Which gives;

[m = 10 kg, r = 0.25·R] > [m = 20 kg, r = 0.25·R] > [m = 10 kg, r = 0.5·R] > [m =

10 kg, r = 0.5·R] = [m = 40 kg, r = 0.25·R] > [m = 10 kg, r = 1.0·R].

Learn more here:

brainly.com/question/15188750

6 0

2 years ago