What is the net force in the following diagram?

Jeff is a landscaping contractor and lifts a rock weighing 600 pounds by wedging a board under the rock. Jeff weighs 150 pounds

jonny [76]

Answer: 4

The mechanical advantage is the ratio of the force exerted by the object to the force applied to do work on it.

Here, Jeff tried to lift a rock weighing 600 pounds by wedging board under the rock. Jeff who weighs 150 pounds uses all his weight to exert force on lever and lift rock.

Mechanical advantage, $M.A.=\frac{weight\hspace{1mm}of\hspace{1 mm}rock}{weight\hspace{1mm}of\hspace{1 mm}Jeff}=\frac{600 pounds}{150 pounds}=4.$

Therefore, the mechanical advantage that lever provided to Jeff in lifting rock is 4.

6 0

2 years ago

Read 2 more answers

Suppose a car travels 106 km at a speed of 28 m/s and uses 1.9 gals of gasoline in the process. Only 30% of the gasoline goes in

USPshnik [31]

Answer:

a) The magnitude of the force is 968 N

b) For a constant speed of 30 m/s, the magnitude of the force is 1,037 N

Explanation:

<em>NOTE: The question b) will be changed in other to give a meaningful answer, because it is the same speed as the original (the gallons would be 1.9, as in the original).</em>

Information given:

d = 106 km = 106,000 m

v1 = 28 m/s

G = 1.9 gal

η = 0.3

Eff = 1.2 x 10^8 J/gal

a) We can express the energy used as the work done. This work has the following expression:

$W=F\cdot d$

Then, we can derive the magnitude of the force as:

$F=\frac{W}{d}=\frac{\eta\cdot (G\cdot Eff)}{d}=\frac{0.3*1.9*(1.8*10^8)}{106*10^3} =968\,N$

b) We will calculate the force for a speed of 30 m/s.

If the force is proportional to the speed, we have:

$F_2=F_1(\frac{v_2}{v_1} )=968(\frac{30}{28} )=968*1.0714=1,037\,N$

6 0

2 years ago

A plane has an airspeed of 142 m/s. A 30.0 m/s wind is blowing southward at the same time as the plane is flying. What must be t

const2013 [10]

Answer:

$\theta=12.19^{\circ}$

Explanation:

Given that

The speed of the airplane ,v= 142 m/s

The speed of the air ,u = 30 m/s

Lets take angle make by airplane from east direction towards north direction is θ .

Now by using diagram ,we can say that

$sin\theta =\dfrac{u}{v}$

Now by putting the values in the above equation we get

$sin\theta =\dfrac{30}{142}$

$sin\theta=0.21$

$\theta=12.19^{\circ}$

Therefore the angle will be 12.19° .

4 0

3 years ago

A sound wave traveling through dry air has a frequency of 15 Hz, a

Korolek [52]

Answer:

Option B

Explanation:

Speed of a wave is denoted by:

v=fλ

where f is the frequency which is unchanged 15Hz and λ is the new wavelength which is 28m

v=fλ

$v=15(28)\\v=420m/s$

3 0

3 years ago

Read 2 more answers

U.

victus00 [196]

Answer:

1. F and G.

2. D

3. A and E.

4. B

5. C

Explanation:

1. Acceleration: An increase in a body's velocity. An increase in a body's speed.

In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.

This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.

2. Kinematics: a study of moving bodies i.e physical objects in motion.

Motion can be defined as a change in the location (position) of a physical object or body with respect to a reference point.

This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.

3. Inertia: A tendency of a body to keep moving. A state of balance of forces on a body and the body remains either at rest or in uniform motion.

Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.

In physics, Sir Isaac Newton's First Law of Motion is known as Law of Inertia and it states that, an object or a physical body in motion will continue in its state of motion at continuous velocity (the same speed and direction) or, if at rest, will remain at rest unless acted upon by an external force.

4. Velocity: Fastness and direction of a body.

Velocity can be defined as the rate of change in displacement (distance) with time. Velocity is a vector quantity and as such it has both magnitude and direction.

5. Reaction: an opposite force.

Newton's third law of motion states that for every action there is an equal and opposite reaction.

Action-reaction force pairs make it possible for fishes to swim, birds to fly, cars to move, etc.

7 0

3 years ago

What is the net force in the following diagram?​

What is the net force in the following diagram?