Compare the motion of an object acted on by balanced forces with the motion of an object acted on unbalanced forces

A 102 kg football player runs at a speed of 8 m/s to sack the quarterback. What is

leva [86]

The mass of the quarterback is 61.2 kg.

Explanation:

mass of the football player = m1 = 102 kg

mass of the quarterback = m2 = ?

velocity of the football player = v1 = 8 m/s

According to the law of conservation of momentum:

The total momentum of a system before and after the collision remains constant. Assuming the situation as an isolated system which is not affected by any external factors, we have:

m₁v₁ + m₂v₂ = (m₁+m₂)V

Here, we need to find m₂.

We assume that the quarterback is standing still when he is attacked by the football player so v₂ = 0 m/s

After the collision both of them fall to the ground with a velocity of 5 m/s so V = 5 m/s

$102(8) + m2(0) = (102 + m2)(5)\\816 + 0 = (102 + m2)(5)\\816/5 = 102 + m2\\163.2 - 102 = m2\\m2 = 61.2 kg$

Keywords: momentum, velocity, law of conservation of momentum

Learn more about Law of Conservation of Momentum from brainly.com/question/7538238

#learnwithBrainly

3 0

4 years ago

g Warm water in a geothermal heating system enters the pipe of a radiator at 20 psia and 119oF with a flow rate of 235 cfm (ft3/

Vika [28.1K]

Answer:

See explanation

Explanation:

Notice that the condenser section includes both the hot water and space heater and station (3) is specified as being in the Quality region. Assume that 50°C is a reasonable maximum hot water temperature for home usage, thus at a high pressure of 1.6 MPa, the maximum power available for hot water heating will occur when the refrigerant at station (3) reaches the saturated liquid state. (Quick Quiz: justify this statement). Assume also that the refrigerant at station (4) reaches a subcooled liquid temperature of 20°C while heating the air.

Using the conditions shown on the diagram and assuming that station (3) is at the saturated liquid state

a) On the P-h diagram provided below carefully plot the five processes of the heat pump together with the following constant temperature lines: 50°C (hot water), 13°C (ground loop), and -10°C (outside air temperature)

b) Using the R134a property tables determine the enthalpies at all five stations and verify and indicate their values on the P-h diagram.

c) Determine the mass flow rate of the refrigerant R134a. [0.0127 kg/s]

d) Determine the power absorbed by the hot water heater [2.0 kW] and that absorbed by the space heater [0.72 kW].

e) Determine the time taken for 100 liters of water at an initial temperature of 20°C to reach the required hot water temperature of 50°C [105 minutes].

f) Determine the Coefficient of Performance of the hot water heater [COPHW = 4.0] (defined as the heat absorbed by the hot water divided by the work done on the compressor)

g) Determine the Coefficient of Performance of the heat pump [COPHP = 5.4] (defined as the total heat rejected by the refrigerant in the hot water and space heaters divided by the work done on the compressor)

h) What changes would be required of the system parameters if no geothermal water loop was used, and the evaporator was required to absorb its heat from the outside air at -10°C. Discuss the advantages of the geothermal heat pump system over other means of space and water heating

4 0

3 years ago

1.What is laser?<br> 2.List the uses of laser in everyday life

oee [108]

Laser means Light Amplication by Stimulated Emission of Radiation.

Uses of laser

DNA sequencing instrument

Cutting and welding materials

Semiconducting chip manufacturing

Military devices

IF YOU LIKE MY ANSWER MARK AS BRAINLIEST

8 0

3 years ago

An inductor in an LC circuit has a maximum current of 2.4 A and a maximum energy of 56 mJ.

Harrizon [31]

Answer:

The energy stored in the capacitor, when the current in the inductor is 1.2 A, is 41.6 mJ.

Explanation:

In a LC oscillating circuit, the energy is stored in the electric field (between the plates of the capacitor) and in the magnetic field (surrounding the wires of the inductor).

At any time, the sum of both energies can be expressed as follows:

E = 1/2 Q² / C + 1/2 L I²

In this type of circuit, energy oscillates, which means that it is exchanging between both fields all time.

When the capacitor is completely discharged, all the energy is stored in the magnetic field, and at that time, the current is maximum.

The total energy, when I is maximum, can be written as follows:

E = 1/2 L I² (1)

In our case, when I= 2.4A, E= 56 mJ.

So, we can find out the value of L, which will allow us to know the value of the magnetic energy at any time, having the value of the instantaneous current.

Solving for L in (1):

L = 2 *.56 mJ / (2.4)² A² = 20 mH

The next step is getting the value of the energy stored in the inductor, when I = 1.2 A, as follows:

Em = 1/2 *20 mH.* (1.2)² A² = 14.4 mJ

As the total energy must be always the same, i.e., 56 mJ, the energy stored in the capacitor, assuming no losses, must be the difference between the total energy and the one stored in the magnetic field:

Ec = 56 mJ - 14.4 mJ = 41.6 mJ

3 0

3 years ago

To practice Problem-Solving Strategy 17.1 for wave interference problems. Two loudspeakers are placed side by side a distance d

Nimfa-mama [501]

Complete Question

The compete question is shown on the first uploaded question

Answer:

The speed is $v = 350 \ m/s$