Please select a subject first
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A metal ball cools from 64 °C to 50 °C in 10 minutes and to 42 °C in next 10 minutes. The ratio of rates of fall of temperature during the two intervals is _______.
Concept: undefined >> undefined
The susceptibility of magnesium at 300 K is 2.4 x 10-5. At what temperature will the susceptibility increase to 3.6 x 10-5?
Concept: undefined >> undefined
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1000 tiny mercury droplets coalesce to form a bigger drop. In this process, temperature of the drop _______ .
(A) increases
(B) may increase or decrease
(C) decreases
(D) does not change
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A body cools from 62°C to 54°C in 10 minutes and to 48°C in the next 10 minutes. Find the temperature of the surroundings.
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The susceptibility of magnesium at 300K is 1.2 x 10-5. At what temperature will the susceptibility increase to 1.8 X 10-5?
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The substance which allows heat radiations to pass through is _______.
(A) iron
(B) water vapour
(C) wood
(D) dry air
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Choose the correct option.
Which of the following is not a fundamental unit?
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Answer the following question.
Define average velocity and instantaneous velocity. When are they same?
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Define the following term:
Free fall
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Answer the following question.
If the motion of an object is described by x = f(t), write formulae for instantaneous velocity and acceleration.
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Answer the following question.
Derive equations of motion graphically for a particle having uniform acceleration, moving along a straight line.
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Solve the following problem.
An aeroplane has a run of 500 m to take off from the runway. It starts from rest and moves with constant acceleration to cover the runway in 30 sec. What is the velocity of the aeroplane at the take-off?
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Solve the following problem.
A car moving along a straight road with a speed of 120 km/hr, is brought to rest by applying brakes. The car covers a distance of 100 m before it stops. Calculate
(i) the average retardation of the car
(ii) time taken by the car to come to rest.
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Solve the following problem.
A car travels at a speed of 50 km/hr for 30 minutes, at 30 km/hr for next 15 minutes and then 70 km/hr for next 45 minutes. What is the average speed of the car?
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Solve the following problem.
A velocity-time graph is shown in the adjoining figure.
Determine:
- the initial speed of the car
- the maximum speed attained by the car
- part of the graph showing zero acceleration
- part of the graph showing constant retardation
- distance travelled by car in the first 6 sec.
Concept: undefined >> undefined
Solve the following problem.
A metro train runs from station A to B to C. It takes 4 minutes in travelling from station A to station B. The train halts at station B for 20 s. Then it starts at station B and reaches station C in next 3 minutes. At the start, the train accelerates for 10 sec to reach a constant speed of 72 km/hr. The train moving at the constant speed is brought to rest in 10 sec. At the next station.
(i) Plot the velocity- time graph for the train travelling from station A to B to C.
(ii) Calculate the distance between the stations A, B and C.
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Answer the following question.
State Kepler’s law of equal areas.
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Answer the following question.
State Kepler’s law of the period.
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Answer the following question in detail.
State Kepler’s three laws of planetary motion.
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Answer in one sentence.
Define elasticity.
Concept: undefined >> undefined
