What is the resultant of a pair of forces, 100N, upward and 75N, downward?

Answer:

Positive work is said to be done when the force acting on a body produces a displacement in the direction of the force. Negative work is said to be done when the force acting on a body produces a displacement opposite to the direction of the force

Explanation:

When the displacement of the body the in the direction of the force then the work done is positive. For example :- a man pushing a car in a straight path.

When the displacement is in a direction opposite to the direction of the force then the work done is said to be negative. For example :- work done by the friction.

57. A 0.530-kg basketball hits a wall head-on with a forward speed of 18.0 m/s. It rebounds with a speed of 13.5 m/s. The contact time is 0.100 seconds. (a) determine the impulse with the wall, (b) determine the force of the wall on the ball.

Answer: Answer: (a) -16.7 N s; (b) -167 N

Given: m = 0.530 kg; vi = 18.0 m/s; vf = 13.5 m/s; t = 0.100 s

Find: (a) Impulse, (b) Force

(a) Impulse = Momentum Change = m•Delta v = m•(vf - vi)= (0.530 kg)•( -13.5 m/s - 18.0 m/s)

Impulse = -16.7 kg•m/s = -16.7 N•s

where the "-" indicates that the impulse was opposite the original direction of motion.

(Note that a kg•m/s is equivalent to a N•s)



(b) The impulse is the product of force and time. So if impulse is known and time is known, force can be easily determined.

Impulse = F•t

F = Impulse/t = (-16.7 N s) / (0.100 s) = -167 N

where the "-" indicates that the impulse was opposite the original direction of motion. 58. A 4.0-kg object has a forward momentum of 20. kg•m/s. A 60. N•s impulse acts upon it in the direction of motion for 5.0 seconds. A resistive force of 6.0 N then impedes its motion for 8.0 seconds. Determine the final velocity of the object.

Answer: vf = 8.0 m/s

This question is best thought about conceptually using the principle that an objects momentum is changed when it encounters an impulse and the amount of change in momentum is equal to the impulse which it encounters.

Here an object starts with 20 units (kg•m/s) of momentum. It then encounters an impulse of 60 units (N•s) in the direction of motion. A 60-unit impulse will change the momentum by 60 units, either increasing or decreasing it. If the impulse is in the direction of an object's motion, then it will increase the momentum. So now the object has 80 units (kg•m/s) of momentum. The object then encounters a resistive force of 6.0 N for 8.0 s. This is equivalent to an impulse of 48 units (N•s). Since this impulse is "resistive" in nature, it will decrease the object's momentum by 48 units. The object now has 32 units of momentum. The question asks for the object's velocity after encountering these two impulses. Since momentum is the product of mass and velocity, the velocity can be easily determined.

p = m•v
vfinal = pfinal / m = (32 kg m/s) / (4.0 kg) = 8.0 m/s. 59. A 3.0-kg object is moving forward with a speed of 6.0 m/s. The object then encounters a force of 2.5 N for 8.0 seconds in the direction of its motion. The object then collides head-on with a wall and heads in the opposite direction with a speed of 5.0 m/s. Determine the impulse delivered by the wall to the object.

Answer: 53 N•s

Like the previous problem, this problem is best solved by thinking through it conceptually using the impulse-momentum change principle.

Here the object begins with a momentum of 18 units (kg•m/s). The object encounters a force of 2.5 N for 8.0 seconds. This is equivalent to an impulse of 20 units (N•s). Since this impulse acts in the direction of motion, it changes the object's momentum from 18 units to 38 units. A final impulse is encountered when colliding with a wall. Upon rebounding, the object has a momentum of -15 units (kg•m/s). The -15 is the product of mass (3 kg) and velocity (-5 m/s). The "-" sign is used since the object is now moving in the opposite direction as the original motion. The collision with the wall changed the object's momentum from +38 units to -15 units. Thus, the collision must have resulted in a 53-unit impulse since it altered the object's momentum by 53 units. 60. A 46-gram tennis ball is launched from a 1.35-kg homemade cannon. If the cannon recoils with a speed of 2.1 m/s, determine the muzzle speed of the tennis ball.

Answer: 62 m/s

Given: mball = 46 g = 0.046 kg; mcannon = 1.35 kg; vcannon = -2.1 m/s

Find: vball = ???

The ball is in the cannon and both objects are initially at rest. The total system momentum is initially 0. After the explosion, the total system momentum must also be 0. Thus, the cannon's backward momentum must be equal to the ball's forward momentum.

mcannon • vcannon = -mball • vball
(1.35 kg) • (-2.1 m/s) = (0.046 kg) • vball

vball = (1.35 kg) • (2.1 m/s) / (0.046 kg) = 61.63 m/s = ~62 m/s. 61. A 2.0-kg box is attached by a string to a 5.0-kg box. A compressed spring is placed between them. The two boxes are initially at rest on a friction-free track. The string is cut and the spring applies an impulse to both boxes, setting them in motion. The 2.0-kg box is propelled backwards and moves 1.2 meters to the end of the track in 0.50 seconds. Determine the time it takes the 5.0-kg box to move 0.90 meters to the opposite end of the track.

Answer:

Gold is a relatively dense metal because its atoms have more protons then atoms of many other metals

Explanation:

Answer:

A moving car possesses mechanical energy due to its motion (kinetic energy). A moving baseball possesses mechanical energy due to both its high speed (kinetic energy) and its vertical position above the ground (gravitational potential energy).

Explanation:

Answer:

Different isotopes of an element have the same number of protons in the nucleus, giving them the same atomic number, but a different number of neutrons giving each elemental isotope a different atomic weight.

Explanation:

Answer:

Different isotopes of an element have the same number of protons in the nucleus, giving them the same atomic number, but each element isotope has a different atomic weight due to the different number of neutrons.

Explanation:

I hope my answer helps u :)

Answer: B replace the battery with a larger one

Explanation: B

Answer:

Replace the wire with one that is thicker.

Explanation:

Answer:

He must be riding on a horse named Saturday.

Explanation:

He rode Saturday on Friday, stayed in the town for 3 days and left on his horse, named Saturday.

I've heard this many times.

he left his house on a Thursday got their on a Friday and left on Saturday Explanation:

this is the best i can do

1. Tissue
2. Organ
3. System

It is an example of rolling friction because balls roll.

Answer is ROLLING

Answer:

Warmer water cannot hold as much dissolved oxygen as cold water can hold, which would increase the number of hypoxic zones/dead zones.

The direction of the induced current is counterclockwise.

What is Lenz law?

This states that induced electric current flows in a direction such that the current opposes the change that induced it.

The direction of the induced current is counterclockwise as a result of the north pole being oriented downwards which is the opposite direction of the hands of a clock movement.

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Answer:

D. Malleable

Explanation:

Gold is metallic, with a yellow colour when in a mass, but when finely divided it may be black, ruby, or purple. It is the most malleable and ductile metal; 1 ounce (28 g) of gold can be beaten out to 300 square feet. It is a soft metal and is usually alloyed to give it more strength.

USDA Food Plan Spending for a Single Person

Low-cost: $222.60. Moderate-cost: $272.20.

Winter
Summer
Fall
Spring
I would go with winter

Answer:

A. Inertia

Explanation:

Answer:

A inertia is directly related to mass

Explanation:

inertia

Answer:

12m / 7.3*10^-2m/cy = 164.38 cycles.

164.38cy / 2cy/s = 82.2s.

Explanation:

Answer:

D.physical model

Explanation:

it is the evolution of butterfly

Answer:

Magnetic forces.

When the magnets are put together, the north pole is attracted to the south pole, which the south pole goes toward the opposing pole on the opposite magnet. Complicated, yes, but how magnets work.

I hope this helps!

Answer:

The correct relationships are T-fg=ma and L-fg=0.

(A) and (C) is correct option.

Explanation:

Given that,

Weight Fg = mg

Acceleration = a

Tension = T

Drag force = Fa

Vertical force = L

We need to find the correct relationships

Using balance equation

In horizontally,

The acceleration is a

[tex]T-Fd=ma[/tex]...(I)

In vertically,

No acceleration

[tex]w=L[/tex]

[tex]mg-L=0[/tex]

Put the value of mg

[tex]L-fg=0[/tex]....(II)

Hence,  The correct relationships are T-fg=ma and L-fg=0.

(A) and (C) is correct option.

In the attached picture we can see the original question.

A water-skier with weight Fg = mg moves to the right with acceleration a. A horizontal tension force T is exerted on the skier by the rope, and a horizontal drag force Fd is exerted by the water on the ski. The water also exerts a vertical lift force L on the skier. The correct relationships are:

(A) [tex]T - F_d = ma[/tex]

(C) [tex]L - F_g = 0[/tex]

A water skier is moving to the right with acceleration a. If we analyze the forces in the horizontal direction, we can identify the tensión force (T), in the direction of the movement and the drag force (Fd), opposing to the movement. According to Newton's second law of motion, the resultant of these forces is equal to the product of the mass of the water skier and its acceleration.

[tex]T - F_d = ma[/tex]

In the vertical direction, we have the weight of the water skier (Fg) and the lift force (L) exerted on the skier by the water. The resultant of these 2 forces is zero, since there is no acceleration in the vertical direction.

[tex]L - F_g = 0[/tex]

A water-skier with weight Fg = mg moves to the right with acceleration a. A horizontal tension force T is exerted on the skier by the rope, and a horizontal drag force Fd is exerted by the water on the ski. The water also exerts a vertical lift force L on the skier. The correct relationships are:

(A) [tex]T - F_d = ma[/tex]

(C) [tex]L - F_g = 0[/tex]

Learn more: https://brainly.com/question/13447525

What’s that? Sorry??

Answer:

Here is what I thought of: Below;

Explanation:

Floods, big or small, can have devastating effects on your home and your family. You can take steps to reduce the harm caused by flooding. Learn how to prepare for a flood, stay safe during a flood, and protect your health when you return home after a flood.

Preparing for a Flood

Learn how to prepare for a flood, including how to create a plan, supplies you’ll need, and getting your home ready.

Floodwater Safety

Floodwater and standing water can be dangerous. Protect yourself and your loved ones from risks brought on by floods.

Returning Home

Returning home after a flood? Be aware that your home may be contaminated with mold or sewage. Take steps to keep yourself and your loved ones safe.

Hope this helps you. :)

Power=P=120WVoltage=V=48VCurrent=I

[tex]\\ \sf\Rrightarrow P=VI[/tex]

[tex]\\ \sf\Rrightarrow 120=48I[/tex]

[tex]\\ \sf\Rrightarrow I=120/48[/tex]

[tex]\\ \sf\Rrightarrow I=2.5A[/tex]

Answer:

The angle between the mirrors is 90°.

Explanation:

Given that,

Number of image = 5

Rahul kept two plane mirrors at a certain angle in front of a burning candle.

We need to find the angle between the mirrors

Using given data

When Rahul kept two plane mirrors at a certain angle in front of a burning candle then see the 5 image of candle in the mirrors.

If rahul kept two plane mirrors at a 90° then we get the 5 image of candle.

Firstly we see the two images in both mirror and now first image of first mirror is see in second mirror and second image of second mirror is see in first mirror.

So, we can say that we see the 5 image of candle in the mirrors.

Hence, The angle between the mirrors is 90°.

Answer: Its applied force and friction, The friction is the drag and the applied force is you pushing

Resulting force is the vector sum of all the forces acting on an object. The resulting net force of →10 N can be represented by ← 63 N and → 73 N

Net force on an object

The net force on an object is the sum of all the forces acting on an object. Resolving the forces in vertical direction and horizontal direction separately gives the net force on the object.

∑Fx = ma

∑Fy = ma

The net force is pointing towards the right and the correct option must contain two horizontal forces whose resultant is towards the right.

Considering following horizontal forces,

← 63 N and → 73 N, the net force = - 63 N + 73 N = 10 N  (→ 10 N)← 97 N and → 87 N, the net force = -97 N + 87 N = -10 N (← 10 N)

Thus, the resulting net force of →10 N can be represented by ← 63 N and → 73 N

Learn more about net force here: https://brainly.com/question/14361879

Answer: C, 63N and 73 N

Explanation:

Answer:   1470 N

Explanation:   mass = 15

                   weight is the product of mass and force due to gravity

                     AS WE KNOW THAT

                        W = mG

                        W = 15 X 9.8

                         W =  1470 N

5.2 m/s. F=ma so 250=48a. Divide 250 by 48 and get your acceleration

Sodium (NA) : it’s outermost electron is 1
It still needs +7for it to be stable
Strontium (sr)

Sulphur(s) : it’s outermost electron is 6 it still needs +2 for it to be stable
Astatine(Ar):

Answer:

If the charges have the same sign, so that qsqt>0, then the potential energy decreases as the charges separate; if the charges have opposite sign, the potential energy increases from negative infinity.

Explanation:

I hope this answered your question!

Answer:

Distance = speed×time = 180×3 = 540 Km

Answer:

44

Explanation:

v=u+a(t)

v=18+4(2)

v=22(2)

v=44 (where v=final velocity,u=initial velocity,a=acceleration,and t=time)

(a) The cost of electricity for one day is Rs. 42 .

(b) The cost of electricity for the month of January​ is Rs. 1,302.

Average energy used

The electric energy consumed in each is calculated as follows;

E = Pt

E = 60 x 6 = 360 Wh

E(total) = 8 x 360 Wh = 2880 Wh

The cost of Electricity is in kWh

2880 Wh = 2.8 kWh

Cost of electricicty for one day

C = 2.8 kWh x (Rs. 15)/kWh

C = Rs. 42

Cost of electricity for the month of January​ (31 days)

C = Rs.42 x 31

C = Rs. 1,302

Learn more about cost of electricity here: https://brainly.com/question/9821162