Advertisements
Advertisements
प्रश्न
The figure shows a light spring balance connected to two blocks of mass 20 kg each. The graduations in the balance measure the tension in the spring. (a) What is the reading of the balance? (b) Will the reading change if the balance is heavy, say 2.0 kg? (c) What will happen if the spring is light but the blocks have unequal masses?
Advertisements
उत्तर
(a)
The reading of the balance = Tension in the string
And tension in the string = 20g
So, the reading of the balance = 20g = 200 N
(b) If the balance is heavy, the reading will not change because the weight of spring balance does not affect the tension in the string.
(c) If the blocks have unequal masses, the spring balance will accelerate towards the heavy block with an acceleration a. Then the reading will be equal to the tension in the string.
Suppose m1 > m2.
Then tension in the string,
\[T = \frac{2 m_1 m_2 g}{m_1 + m_2}\].
APPEARS IN
संबंधित प्रश्न
A batsman hits a cricket ball which then rolls on a level ground. After covering a short distance, the ball comes to rest. The ball slows to a stop because ______.
Give the magnitude and direction of the net force acting on a drop of rain falling down with a constant speed.
The driver of a three-wheeler moving with a speed of 36 km/h sees a child standing in the middle of the road and brings his vehicle to rest in 4.0 s just in time to save the child. What is the average retarding force on the vehicle? The mass of the three-wheeler is 400 kg and the mass of the driver is 65 kg.
Name the scientist who gave the laws of motion.
Fill in the following blank with suitable word :
Newton’s first law of motion is also called Galileo’s law of ………………………
Name the physical quantity whose unit is ‘newton’.
A block of mass 10 kg is suspended from two light spring balances, as shown in the following figure.
Neglect the effect of rotation of the earth. Suppose the earth suddenly stops attracting objects placed near its surface. A person standing on the surface of the earth will.
A reference frame attached to the earth
(a) is an inertial frame by definition
(b) cannot be an inertial frame because the earth is revolving around the sun
(c) is an inertial frame because Newton's laws are applicable in this frame
(d) cannot be an inertial frame because the earth is rotating about its axis.
The force exerted by the floor of an elevator on the foot of a person is more than the weight of the person if the elevator is
(a) going up and slowing down
(b) going up and speeding up
(c) going down and slowing down
(d) going down and speeding up
'When a hanging carpet is beaten with a stick, the dust particles start coming out of it'. This phenomenon can be best explained by making use of :
Explain the following :
After alighting from a moving bus , one has to run for some distance in the direction of bus in order to avoid falling .
Name the different kinds of inertia an object can possess. Give an example of each.
The amount of inertia of a body depends on its _________.
Name the scientist who first stated the law of inertia.
Match the following
| Column I | Column II |
| Newton’s I law | propulsion of a rocket |
| Newton’s II law | Stable equilibrium of a body |
| Newton’s III law | Law of force |
| Law of conservation of linear momentum | Flying nature of bird |
If a 5 N and a 15 N forces are acting opposite to one another. Find the resultant force and the direction of action of the resultant force.
When a bus suddenly takes a tum, the passengers are thrown outwards because of
A smooth sphere of radius R and mass M is placed on the smooth horizontal floor. Another smooth particle of mass m is placed on the sphere and a horizontal force F is applied on the sphere as shown. If the particle does not slip on the sphere then the value of force F is ______.
What is the significance of Newton’s first law?
