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2 years ago

A person is lifting a heavy box using a lever. What is the purpose of the lever in this situation?

Physics

1 answer:

ruslelena [56]2 years ago

6 0

Answer:

to reduce the force needed to lift the box and change the direction of the force

Explanation:

1. "A lever consists of a rigid bar that is able to pivot at one point. This point of rotation is known as the fulcrum. A force is applied at some point away from the fulcrum (typically called the effort)."

By this definition, we know that force is needed to lift an object using a lever.

2. "When the input and output forces are on opposite sides of the fulcrum, the lever changes the direction of the applied force. This occurs only with first-class levers. When both the input and output forces are on the same side of the fulcrum, the direction of the applied force does not change"

For example, on a sew saw, if a force is applied on one end, you on the other side/end would go up, meaning a change in direction.

3. Lastly, we know a lever is typically used to reduce work, in other words, the force needed to move something.

Basically, if we were to put a lever into an equation:

reduced force + change in direction = lever

(the expection) unless load and force are on the same side, there will be no change in direction.

For example, if you and your friend sit on the same side of a sew saw, the sew saw would not go up or down, meaning no change in direction.

So if not stated otherwise you can assume the load and force are on opposite sides. The purpose of a lever in that situation would be to reduce the force needed to lift the box and change the direction of the force.

*While reading my explanation, it may be helpful to look up a diagram containing a lever, with a load, fulcrum, and applied force.

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An engineer designs a roller coaster so that a car travels horizontally for 162 ft, then climbs 137 ft at an angle of 31.0° abov

Zielflug [23.3K]

Answer:

Explanation:

We know that

Δr = r₁ - r₀

r₀ = 0 i + 0 j

r₁ = (162+137*Cos(31º)+137*Cos(-48º)) i + (0+137*Sin(31º)+137*Sin(-48º)) j = (371.1028 i - 31.2506 j) ft

Δr = r₁ - r₀ = (371.1028 i - 31.2506 j) - (0 i + 0 j) = (371.1028 i - 31.2506 j) ft

Magnitude:

Δr = √((371.1028)²+(-31.2506)²) = 372.4163 ft

Angle:

tan θ = (- 31.2506 / 371.1028) = -0.0839 ⇒ θ = tan⁻¹(-0.0839) = - 4.8135º

(below the horizontal).

8 0

4 years ago

A student places a block on a table and hangs one mass from the block. The student lets the block go and observes the block move

NeTakaya

Magnitude of acceleration

Explanation:

We know that acceleration can increase depending in the force applied on an object, any object with a greater mass will apply a greater force. F = M(a).

7 0

3 years ago

Calculate the Fermi energy and the conductivity at room temperature for germanium containing 5×10^16 arsenic atoms per cubic cen

Cloud [144]

Answer:

The Fermi energy is 0.568 eV and the conductivity at room temperature is 31.24 (Ωcm)⁻¹

Explanation:

Data given:

Nd = doping concentration = 5x10⁶/cm³

According the mass action law, the hole concentration is:

$P_{0} =\frac{n_{i}^{2} }{n_{0} } ,n_{i}=2x10^{13} /cm^{3}$

$E_{f} =E_{i} +KTln(\frac{n_{D} }{n_{i} } ),K=8.61x10^{-19} ,KT=0.026eV$

$E_{i} =\frac{E_{0} }{2} =\frac{0.63}{2} =0.315eV\\E_{f}=0.315+0.203=0.568eV$

The conductivity of n-type of semi-conductor is equal to:

The mobility of Germanium is 3900 cm²/Vs

σ = 1.6x10⁻¹⁹ * 5x10¹⁶ * 3900 = 31.24 (Ωcm)⁻¹

6 0

3 years ago

Physics is killing me. Any help?

Anni [7]

Answer:

The simplified expression is 3.833 x 10⁷ g

Explanation:

Given expression;

3.88 x 10⁷ g - 4.701 x 10⁵ g

The expression above is simplified as follows;

= (3.88 x 100 x 10⁵ )g - ( 4.701 x 10⁵) g

= (388 x 10⁵ )g - ( 4.701 x 10⁵) g

= (388 - 4.701 ) x (10⁵ )g

= 383.299 x 10⁵ g

In standard form, the simplified expression can be expressed as;

= (3.83299 x 100 x 10⁵) g

= 3.83299 x 10⁷ g

= 3.833 x 10⁷ g

Therefore, the simplified expression is 3.833 x 10⁷ g

5 0

3 years ago

What is the difference between dynamics and kinematics

stira [4]

Answer:

Kinematics is the study of how things move while dynamics is the study of forces and motion

5 0

2 years ago