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3 years ago

John pushes a box with a constant force as shown in the graph below.

Physics

1 answer:

andrew11 [14]3 years ago

4 0

From the graph, it can be seen that the constant force that John exerted in order to move the object is 14N. Work is calculated by multiplying the force with the distance to which the object moves in parallel with the direction of the force.
Work = Force x displacement
Work = (14 N) x (8 m)
Work = 112 J
The closest value is 110J. Thus, the answer to this item is the second choice.

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For the circuit shown in the figure(figure 1) find the current through each resistor. Express your answers using two significant

Angelina_Jolie [31]

The current flowing in each resistor of the circuit is 4 A.

<h3>Equivalent resistance of the series resistors</h3>

The equivalent resistance of the series circuit is calculated as follows;

6 Ω and 4 Ω are in series = 10 Ω

5 Ω and 10Ω are in series = 15 Ω

<h3>Effective resistance of the circuit</h3>

$\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2} \\\\R = \frac{R_1R_2}{R_1 + R_2} \\\\R = \frac{10 \times 15}{10 + 15} \\\\R = 6 \ ohms$

<h3>Current flowing in the circuit</h3>

V = IR

I = V/R

I = 24/6

I = 4 A

Learn more about resistors in parallel here: brainly.com/question/15121871

8 0

1 year ago

How much thermal energy is created in the slope and the tube during the ascent of a 30-m-high, 120-m-long slope?

charle [14.2K]

<span>The change in internal energy is only gravitional PE because the tube is being drug up at a constant speed. Since it is at a constant speed, the change in KE is 0. Change in PE = m*g*h = 78 kg * 10 m/s^2 * 30 m = 23400 J Work done on the system is from the force Work = force * distance = 350 N * 120 m = 42000 J So, work added 42000 J to the system, but the rider's energy only increased 23400 J. Therefore, friction took up the difference. Friction is where the thermal energy comes from Q = 42000 J - 23400 J = 18600 J. Therfore, friction generated 18600 J of heat to the surroundings.</span>

7 0

3 years ago

An artist working on a piece of metal in his forging studio plunges the hot metal into oil in order to harden it. The metal piec

lutik1710 [3]

Answer:

The temperature of the metal is $T_m = 376.8 ^o C$

Explanation:

From the question we are told that

The mass of the metal is $M = 60 \ kg$

The specific heat of the metal is $c_p = 0.1027 kcal/(kg \cdot ^oC)$

The mass of the oil is $M_o = 810 \ kg$

The temperature of the oil is $T_o = 35^oC$

The specific heat of oil is $c_o = 0.7167 kcal/(kg \cdot ^oC )$

The equilibrium temperature is $T_e = 39 ^oC$

According to the law of energy conservation

Heat lost by metal = heat gained by the oil

The quantity of heat lost by the metal is mathematically represented as

$Q = - Mc_p \Delta T$

=> $Q = -Mc_p (T_m - T_c)$

Where $T_ m$ the temperature of metal before immersion

The negative sign show heat lost

The quantity of gained t by the metal is mathematically represented as

$Q = M_o c_o \Delta T$

=> $Q = M_o c_o (T_c - T_o)$

$Mc_p (T_m - T_c) = M_o c_o (T_c - T_o)$

substituting values

$- 60 * 0.1027 (T_m - 39) = 810 * 0.7167 * (39 - 35)$

=> $T_m = 376.8 ^o C$

6 0

3 years ago

Name of a body that changes Chemical energy to electric energy.

Ratling [72]

Answer:

battery

Explanation:

A battery contains stored chemical energy and converts it to electrical energy. (cK.12)

6 0

3 years ago

Why is it important to understand the concept of density ?

N76 [4]

Density applies to many if not all aspects of life. With density you can explain why ice floats. You can explain why oxygen is on the earth, and not floating around in space( or being replaced by another gas). You can also explain why heat rises while cold air sinks.

8 0

2 years ago