If an experiment used 945 j of heat, how many calories (cal) is that?

One end of a thin rod is attached to a pivot, about which it can rotate without friction. Air resistance is absent. The rod has

Scrat [10]

Answer:

5.24 m/s

Explanation:

So for the rod to be able to rise upward to the straight up position, the kinetic energy caused by linear speed v0 must be just enough to convert into the potential energy.

Since the rod is uniform in mass, we can treat the body as 1 point, at its center of mass, or geometric center, aka 0.35 / 2 = 0.175 m from the pivot.

For the rod to swing from bottom to top, the center must have moved a distance of h = 0.175 * 2 = 0.35 m, vertically speaking.

Since we neglect friction and air resistance, according to the law of energy conservation then:

$E_k = E_p$

$mv^2/2 = mgh$

Where v is the speed at the center of mass, g = 9.81 m/s2 is the gravitational acceleration, and m is the mass. We can divide both sides by m

$v^2 = 2gh = 2*9.81*0.35 = 6.867$

$v = \sqrt{6.867} = 2.62 m/s$

As this is only the speed at the center of mass, the speed at the bottom end would be different, to calculate this, we need to find the common angular speed:

$\omega = v / r = 2.62 / 0.175 = 14.97 rad/s$

Where r is the rotation radius, or the distance from pivot point to the center of mass

$v_0 = \omega R = 14.97*0.35 = 5.24 m/s$

Where R is the distance from the pivot to the bottom end of the rod

5 0

3 years ago

The force that binds atoms together to form molecules is

DIA [1.3K]

Answer:

The electromagnetic force

Explanation:

There are four fundamental forces in nature:

- Gravitational force: it is the force that acts between any particles having mass. It is relevant only on very large scales (planets, stars), since it is the weakest of the 4 forces, so very large masses are needed in order to produce relevant effects.

- Electromagnetic force: it is the force that acts between particles with electric charge. It can be attractive or repulsive. It is the main force that acts between atoms and molecules.

- Strong nuclear force: it is the force that keeps the protons and the neutrons together inside the nucleus. It acts only on very short scales (only within the nucleus of the atom)

- Weak nuclear force: it is the force responsible for the radioactive decays of certain nuclei. It also acts on very short scales.

Therefore, the force that is responsible for binding atoms together to form molecules is the electromagnetic force.

7 0

3 years ago

There is a parallel plate capacitor. Both plates are 4x2 cm and are 10 cm apart. The top plate has surface charge density of 10C

liberstina [14]

Answer:

1) The total charge of the top plate is 0.008 C

b) The total charge of the bottom plate is -0.008 C

2) The electric field at the point exactly midway between the plates is 0

3) The electric field between plates is approximately 1.1294 × 10¹² N/C

4) The force on an electron in the middle of the two plates is approximately 1.807 × 10⁻⁷ N

Explanation:

The given parameters of the parallel plate capacitor are;

The dimensions of the plates = 4 × 2 cm

The distance between the plates = 10 cm

The surface charge density of the top plate, σ₁ = 10 C/m²

The surface charge density of the bottom plate, σ₂ = -10 C/m²

The surface area, A = 0.04 m × 0.02 m = 0.0008 m²

1) The total charge of the top plate, Q = σ₁ × A = 0.0008 m² × 10 C/m² = 0.008 C

b) The total charge of the bottom plate, Q = σ₂ × A = 0.0008 m² × -10 C/m² = -0.008 C

2) The electrical field at the point exactly midway between the plates is given as follows;

$V_{tot} = V_{q1} + V_{q2}$

$V_q = \dfrac{k \cdot q}{r}$

Therefore, we have;

The distance to the midpoint between the two plates = 10 cm/2 = 5 cm = 0.05 m

$V_{tot} = \dfrac{k \cdot q}{0.05} + \dfrac{k \cdot (-q)}{0.05} = \dfrac{k \cdot q}{0.05} - \dfrac{k \cdot q}{0.05} = 0$

The electric field at the point exactly midway between the plates, $V_{tot}$ = 0

3) The electric field, 'E', between plates is given as follows;

$E =\dfrac{\sigma }{\epsilon_0 } = \dfrac{10 \ C/m^2}{8.854 \times 10^{-12} \ C^2/(N\cdot m^2)} \approx 1.1294 \times 10^{12}\ N/C$

E ≈ 1.1294 × 10¹² N/C

The electric field between plates, E ≈ 1.1294 × 10¹² N/C

4) The force on an electron in the middle of the two plates

The charge on an electron, e = -1.6 × 10⁻¹⁹ C

The force on an electron in the middle of the two plates, $F_e$ = E × e

∴ $F_e$ = 1.1294 × 10¹² N/C × -1.6 × 10⁻¹⁹ C ≈ 1.807 × 10⁻⁷ N

The force on an electron in the middle of the two plates, $F_e$ ≈ 1.807 × 10⁻⁷ N

4 0

2 years ago

Need help with this<br> THANKS TO WHO HELPS <3

nekit [7.7K]

Answer:

because it's north

Explanation:

u if yyggggggggggggggg hgfth

8 0

2 years ago

Read 2 more answers

A 3 kg bowling ball is thrown onto a mattress. If it takes 0.3 seconds to stop the ball using a force of 24 N, what was the init

enyata [817]

Answer:

-24 m/s

Explanation:

mass of the bowling ball = 3 kg

time (t) = 0.3 seconds

Force = 24 N

initial velocity u = ???

We know that;

Force = mass × acceleration (a)

So;

24 = 3 × a

a = 24/3

a = 8 m/s²

Also;

From equation of motion; acceleration is given by the relation;

$a =\frac{v-u}{t}$

if v = 0

then ;

$8 = \frac{0-u}{0.3}$

24 = 0- u

u = -24 m/s

Thus; the initial velocity of the bowling ball when it first touched the mattress = -24 m/s

7 0

3 years ago