Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics gravitation tides movements of ocean and sea water circulation of ocean water

What are known as tides?

  1. Alternating rise and fall in sea level with respect to land

  2. Alternating rise in sea level with respect to land

  3. Alternating fall in sea level with respect to land

  4. None
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Rise and fall of the surface of the Earth's water body due to the gravitation pull of the Moon and the Sun on the Earth is tides.

Multiple choice physics gravitation tides movements of ocean and sea water circulation of ocean water

What are known as neap tides?

  1. When sun and moon are not aligned tides are not as high and low

  2. When sun and moon are aligned tides are not as high and low

  3. When sun and moon are not aligned tides are as high and low

  4. None
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Tide where the difference between the high tide and low tide is the least is called a neap tide. Such tides occur when the Sun and the Moon are in a right angled position with the Earth. This happens twice in a month.

Multiple choice physics gravitation tides movements of ocean and sea water circulation of ocean water

The type of Gravitational Force that causes tides is known as:

  1. Nuclear Force

  2. Tractive Force

  3. Tidal Force

  4. Wave Force
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Tides are caused by the combined gravitation attraction of the Sun and Moon on the Earth. Force that results in a motion between a body and a tangential surface is called a tractive force.

Multiple choice physics gravitation tides movements of ocean and sea water circulation of ocean water

The tidal waves in the seas are primarly due to

  1. the gravitational effect of the Sun on the Earth.

  2. the gravitational effect of the Moon on the Earth.

  3. the rotation of the Earth.

  4. the atmospheric effect of the Earth on itself.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Although tides are caused due to all the above reasons, the main reason behind it is the gravitational effect of the Moon on the Earth. Moon is closed in a bound state with Earth, and due to this the effect of its gravitation is more on Earth than that of Moon on Earth.

Multiple choice physics turning effects of forces stability and centre of mass center of mass centre of mass

Two bodies of masses 10 kg and 2 kg are moving with velocities $2\hat { i } -7\hat { k } +3\hat { j }\ m{ s }^{ -1 }$ and $-10\hat { i } +35\hat { k } -3\hat { j }\ m{ s }^{ -1 }$ respectively. The velocity of their centre of mass is

  1. $2\hat { i }\ m{ s }^{ -1 }$
  2. $2\hat { j }\ m{ s }^{ -1 }$
  3. $\left( 2\hat { j } +2\hat { k } \right) m{ s }^{ -1 }$
  4. $\left( 2\hat { i } +2\hat { j } +2\hat { k } \right) m{ s }^{ -1 }$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
$m _1 = 10\ kg\quad \vec {v _1}=2\hat i -7\hat k+3\hat j\ m/s$
$m _2=2\ kg \quad \vec {v _2}=-10\hat i +35\hat k-3\hat j\ m/s$
velocity of centre of mass should be
$\vec {v}=\dfrac {m _1 \vec {v _1}+m _2 \vec {v _2}}{m _1 +m _2}$
or $\vec {v}=\dfrac {20\hat i-70\hat k+30\hat j+(-20\hat i+70\hat k-6\hat j)}{10+2}$
$\Rightarrow \ \boxed {\vec {v}=\dfrac {24\ \hat j}{12}=2\hat j\ m/s}$