Which is an si metric unit of measurement that is used to record the heat transfer of a solution in a classroom investigation?

A merry-go-round with a rotational inertia of 600 kg m2 and a radius of 3.0 m is initially at rest. A 20 kg boy approaches the m

nekit [7.7K]

Answer:

The velocity of the merry-go-round after the boy hops on the merry-go-round is 1.5 m/s

Explanation:

The rotational inertia of the merry-go-round = 600 kg·m²

The radius of the merry-go-round = 3.0 m

The mass of the boy = 20 kg

The speed with which the boy approaches the merry-go-round = 5.0 m/s

$F_T \cdot r = I \cdot \alpha = m \cdot r^2 \cdot \alpha$

Where;

$F_T$ = The tangential force

I = The rotational inertia

m = The mass

α = The angular acceleration

r = The radius of the merry-go-round

For the merry go round, we have;

$I_m \cdot \alpha_m = I_m \cdot \dfrac{v_m}{r \cdot t}$

$I_m$ = The rotational inertia of the merry-go-round

$\alpha _m$ = The angular acceleration of the merry-go-round

$v _m$ = The linear velocity of the merry-go-round

t = The time of motion

For the boy, we have;

$I_b \cdot \alpha_b = m_b \cdot r^2 \cdot \dfrac{v_b}{r \cdot t}$

Where;

$I_b$ = The rotational inertia of the boy

$\alpha _b$ = The angular acceleration of the boy

$v _b$ = The linear velocity of the boy

t = The time of motion

When the boy jumps on the merry-go-round, we have;

$I_m \cdot \dfrac{v_m}{r \cdot t} = m_b \cdot r^2 \cdot \dfrac{v_b}{r \cdot t}$

Which gives;

$v_m = \dfrac{m_b \cdot r^2 \cdot \dfrac{v_b}{r \cdot t} \cdot r \cdot t}{I_m} = \dfrac{m_b \cdot r^2 \cdot v_b}{I_m}$

From which we have;

$v_m = \dfrac{20 \times 3^2 \times 5}{600} = 1.5$

The velocity of the merry-go-round, $v_m$ , after the boy hops on the merry-go-round = 1.5 m/s.

5 0

2 years ago

Apakah yang berlaku kepada kekuatan medan magnet jika satu lagi sel kering 1.5 v ditambahkan

ad-work [718]

Answer:

The magnetic field is doubled.

Explanation:

What happens to the strength of the magnetic field if one more 1.5 v dry cell is added?

The magnetic field due to a current carrying conductor is directly proportional to the current flowing in the wire.

If we connect one more battery of 1.5 V so the voltage is doubled and according to the Ohm's law, as the resistance of wire is constant, so the current in the wire is also doubled.

When the current doubles, the magnetic field produced by the wire is also doubled.

8 0

2 years ago

A briefcase sits stationary in an elevator. The mass of the briefcase if 4.5 kg. The elevator then begins accelerating upwards a

Korvikt [17]

Answer:

D. 48.985 N

Explanation:

Newton's second law states that:

$\sum F = ma$

which means that the net force acting on an object is equal to the product between the object's mass and its acceleration.

The equation of the forces for the briefcase in the elevator therefore is given by:

$N-mg=ma$

where

N is the normal reaction exerted on the briefcase

(mg) is the weight of the briefcase, with

m = 4.5 kg being its mass

g = 9.8 m/s^2 is the acceleration of gravity

a = 1.10 m/s^2 is the acceleration

Here we chose upward as positive direction.

Solving for N, we find the normal force:

$N=mg+ma=m(g+a)=(4.5)(9.81+1.10)=49.095 N$

So the closest answer is

D. 48.985 N

3 0

3 years ago

What parent function have all real numbers

alexdok [17]

What are the functions?

4 0

3 years ago

The Sankey diagrams below show the energy transfers in two light bulbs. How much energy is wasted by light bulb 2?

Law Incorporation [45]

Answer:

The amount of energy wasted by light bulb 2 = 70 J

Explanation:

Sankey diagrams are used to graphically indicate the proportional flow rate of a quantity

The labelled Sankey diagrams, here, indicate the energy transfers in two light bulbs, light bulb 1 and light bulb 2

From the labelled Sankey diagrams, we have;

For light bulb 1, the input energy = 80 J

The useful energy = 40 J

The wasted energy = 80 - 40 = 40 J

For light bulb 2, the input energy = 80 J

The useful energy = 10 J

Therefore, the wasted energy = 80 - 10 = 70 J

The amount of energy wasted by light bulb 2 = 70 J.

5 0

3 years ago