Which statement is not correct about force.

A pesky rabbit has been feeding on Mrs. Cromwell’s prized flowers. In order to put an end to this she devised the simple trap be

Ivahew [28]

Answer:

The minimum diameter of the stick to bear the normal stress as 100 psi is 0.1785 in.

Explanation:

Taking moment along point A

$\sum M_A=0\\F_{BC} sin 60 \times 48 -13 \times 8=0\\F_{BC}=2.502 lb_f$

Also normal stress is given as 100 psi

Now

$\sigma=\frac{F}{A}\\100=\frac{2.502}{\pi \frac{d^2}{4}}\\d^2 =\frac{4 \times 2.502}{100 \pi }\\d^2=0.031856\\d=\sqrt{0.031856}\\d=0.1785 inch$

The minimum diameter of the stick to bear the normal stress as 100 psi is 0.1785 in.

4 0

3 years ago

The video shows a collapsing cloud of interstellar gas, which is held together by the mutual gravitational attraction of all the

Aleonysh [2.5K]

The overall force of gravity becomes stronger and stronger. This is because the gravity depends on the inverse of the square of the distance:
$F=G \frac{m_1 m_2}{r^2}$
and since the distance r between the molecules becomes smaller, the gravity increases more and more.

5 0

3 years ago

A 2137 kg car moving east at 12.91 m/s collides with a 3264 kg car moving north. The cars stick together and move as a unit afte

IRINA_888 [86]

Answer:

The speed of the 3264 kg car before collision is 6.32 m/s

Explanation:

Let first car, mass m₁, moving east be moving with velocity, v₁ and second car, mass m₂, moving north be moving with velocity, v₂. Let the velocity of the two cars after collision be v₃

In a Collison (whether elastic or inelastic), momentum is always conserved.

Momentum before collision = momentum after collision.

Momentum before collision = m₁v₁ + m₂v₂

v₁ = (12.91î) m/s in vector form, m₁ = 2137 kg

v₂ = ?, v₂ = (v₂j) m/s in vector form, m₂ = 3264 kg

Momentum before collision = (2137)(12.91î) + (3264)(v₂j) = (27590î + 3264v₂j) kgm/s

Momentum after collision = (total mass of the cars after collision) × (velocity of the stuck-together cars after collision)

Total mass of the cars after collision = m₁ + m₂ = 2137 + 3264 = 5401 kg

Velocity after collision, v₃ = 6.38 m/s In the N36.8°E direction, put in vector form,

v₃ = (6.38 cos 36.8°î + 6.38 sin 36.8°j)

v₃ = (5.11î + 3.82j) m/s

Momentum after collision = 5401 (5.11î + 3.82j) = (27590î + 20641.4j) kgm/s