Answer:
A
Explanation:
because she wants to practice science and A is the practical option.
Answer:
The shearing stress is 10208.3333 Pa
The shearing strain is 0.25
The shear modulus is 40833.3332 Pa
Explanation:
Given:
Block of gelatin of 120 mm x 120 mm by 40 mm
F = force = 49 N
Displacement = 10 mm
Questions: Find the shear modulus, Sm = ?, shearing stress, Ss = ?, shearing strain, SS = ?
The shearing stress is defined as the force applied to the block over the projected area, first, it is necessary to calculate the area:
A = 40*120 = 4800 mm² = 0.0048 m²
The shearing stress:

The shearing strain is defined as the tangent of the displacement that the block over its length:

Finally, the shear modulus is the division of the shearing stress over the shearing strain:

"2 km/hr/s" means that in each second, its engines can increase its speed by 2 km/hr.
If it keeps doing that for 30 seconds, its speed has increased by 60 km/hr.
On top of the initial speed of 20 km/hr, that's 80 km/hr at the end of the 30 seconds.
This whole discussion is of <em>speed</em>, not velocity. Surely, in high school physics,
you've learned the difference by now. There's no information in the question that
says anything about the train's <em>direction</em>, and it was wrong to mention velocity in
the question. This whole thing could have been taking place on a curved section
of track. If that were the case, it would have taken a team of ace engineers, cranking
their Curtas, to describe what was happening to the velocity. Better to just stick with
speed.
Answer:
(a) 0.061 m/s
(b) 0.103 m/s
Explanation:
From the law of conservation of momentum, the sum of initial momentum equals the sum of final momentum
Momentum, p=mv where m is the mass and v is the velocity
where
is the common velocity,
is the velocity of the ball
and
are masses of the ball and person respectively
Substituting the given values then

(b)
Momentum, p=mv where m is the mass and v is the velocity

is the velocity of the ball ,
is the velocity of ball afterwards and
is your speed,
and
are masses of the ball and person respectively. Since it bounces back, we give it a negative value hence

Answer: i think c
Explanation:QA: “What is ordinary glass made of ?”
Glass is mostly silica, or silicon dioxide, present as quartz in many types of sand. Pure silica forms a highly transparent glass, but has a very high melting or softening temperature, around 1700°C. Even at such high temperatures it is highly viscous and difficult to work. Its use is largely confined to applications requiring high transparency to ultra-violet and infra-red radiation, stability at elevated temperatures or low thermal expansion coefficient.
“Ordinary glass” windows and drinking vessels are typically made from soda-lime glass, containing silica with around 25% sodium, calcium and other oxides, which together reduce the softening temperature to roughly 500–600°C