Tag: physics

Questions Related to physics


Spring tides are especially strong tides. Is statement true or false

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

  1. True

  2. False

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Correct Option: B
Explanation:

Tide with the greatest difference between the high and low tide, that occurs just after a new or full moon is a spring tide.

Hence, these tides are the strongest tides.

What are known as tides?

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

  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

Show answer
Correct Option: A
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.

Which tides occur when gravitational forces of Moon and Sun are perpendicular to one another?

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

  1. Spring Tides

  2. Neap Tides

  3. Monsoon Tides

  4. Summer Tides

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Correct Option: B
Explanation:

Neap tides occur twice a month when the Sun and Moon make a angle of 90 degree with the Earth. Such tides are the weakest tides.

When does neap tides occur?

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

  1. During quarter moons

  2. During full moons

  3. During new moons

  4. During half moons

Show answer
Correct Option: A
Explanation:

Neap tides are the tides with the least difference between the high and low tide. Neap tides occur just after the first or third quarters of the Moon.

What are known as neap tides?

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

  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

Show answer
Correct Option: A
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.

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

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

  1. Nuclear Force

  2. Tractive Force

  3. Tidal Force

  4. Wave Force

Show answer
Correct Option: B
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.

The main cause of tides in an ocean is the gravitational pull of:

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

  1. Moon

  2. Sun

  3. Saturn

  4. Mars

Show answer
Correct Option: A
Explanation:

The main cause of tides in an ocean is the gravitational pull of the Moon on the Earth.

The tidal waves in the seas are primarly due to

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

  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.

Show answer
Correct Option: B
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.

The reduce mass of two particles having masses m and 2 m is 

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

  1. 2 m

  2. 3 m

  3. $\dfrac {2 m}{3}$

  4. $\dfrac { m}{2}$

Show answer
Correct Option: C
Explanation:

Given,

$m _1=m$
$m _2=2m$

The reduced mass of two particle system is given by
$\mu=\dfrac{m _1m _2}{m _1+m _2}$

$\mu=\dfrac{m\times 2m}{m+2m}$

$\mu=\dfrac{2m}{3}$
The correct option is C.

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

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

  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. $\left( 2\hat { i } +2\hat { j } +2\hat { k } \right) m{ s }^{ -1 }$

Show answer
Correct Option: B
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 $\vec {v}=\dfrac {20\hat i-70\hat k+30\hat j+(-20\hat i+70\hat k-6\hat j)}{10+2}$
$\Rightarrow \ \boxed {\vec {v}=\dfrac {24\ \hat j}{12}=2\hat j\ m/s}$