hey guys here are the First term questions physics try to solve it please - Physics -

Question

hey guys
here are the First term questions physics try to solve it please
give me the answers too im worried thanks
1)define light years and express it in metres
2)how many nanometres are there in one metre?
3)round off the following numbers to 3 significant figures: 129
855kg , 2099 55m^3
4)if p=a^5, then relative error in p would bee how many times
the relative error in a?
5)under what condition will the distance and displacement of
moving object have the same magnitude?a
6)the displacement of a body is given to be proportional to the
cube of time elapsed what is the nature of the acceleration of the
body?
7)what should be the angle between two vectors A and B for their
resultant R to be maximum
8)a body is projected with speed u at an angle teta (0 ) to the
horizontal to have maximum range what isthe velocity at the highest
point?
9)write the dimensionalformula ofthe following physical
quantities i)powerii)angular velocity iii)resistance iv)plank's
constant
10)Define the following terms
a Absolute error b percentage error
11 The mass nd radius of the earth are5 975 x 10^24 kg and 6 37
x 10^6 m respectively Calculate the average earth's density to
correct significant figures [Take pi = 3 142]
12 When white light travels through glass, the refractive index
of glass (n=velocity of light in air/velocity of light glass) is
foung to vary with wavelengthn as n = a + B/ Using the principle of
homogenity of dimensions, find the SI units in whichn constants A
and B must be expressed
13 The heat dissipated in a reistance can be determined from the
relation : H = I^2Rt/4 2 Cal
If the maximum errors in measurement of current, reistance and
time are 2%, 1% and 15% respectively what would be the maximum
error in the dissipated heat ?
The celocity of a body which ha fallen freely under gravity
varies as g^p h^q, there is the acceleration due to gravity at the
place and 'h' is the height through which the body has fallen
Determine the values of p and q
14 Prove that vector addition is associative
15 Two stright lines drawn on the same displacement - time graph
make angles 30degree and 60 degree with time - axis Which line
represents greater velocity What is the ratio of the two
velocities
16 Accelertion -time graph of moving ohject is shown in figure
Draw the velocity - time graph and displacement - tiome graph
corresponding this motion
17 An aeroplane takes off at an angle of 30 degree to the
horizondal If the component of its velocity along the horozondal is
250 k m per hour, what is its actual velocity? Find also the
vertical component of velocity ?
18 Find the velocity of a projectile for which its maximum
horizondal range is 39 2 m
19 When 1 m, 1 kg, and 1 minute are taken as fundamental units,
the magnitude of force is 36 units What will be the value of this
force in CGS system ?
OR
A gas bubble, from an explosion under water, oscillates with a
period T proportional to p^a,d^b,E^c, where p is the static
pressure, d is the density of water and E is the total energy of
the explosion find the value of a ,b , c
20 distinguish between systematic and random errors how are
these errors minimised
21 in an experiment to determine the specific resistance of a
material the following data was obtained -> resistance
R=(6+or-2) ohm length l=(156+or-0 1)cm and radiusr =(0 26+or-0
02)cm given s =(pi *r^2 *R)/l find the 5error in s
22 when a heavenly body is observed from two diametrically opp
points a and b is on the surface of earth, the parallax made is 60
seconds if the diam of earth is 1 276*10^7 m, find the distance of
the heavenly body from earth express in A U
23 explain the term resolution of a vector how will you resolve
a vector into two rectangular components
24 a cyclist starts from the centre 'O' of aa circular park of
radius 1km reaches the edge P of the park then cycles along the
circumference and returns to the centre along radius (angle
subtended by the radii path=90 therefore it is a quadrnt) if the
round trip takes 10 mins,what is the a net displacement b avg
velocity c avg speed of the cyclist
25 explain the termrelative velocity of a body w r t another
body obtain an expression for the same
MORE 5 MARK QUESTIONS TOMORROW THNK YOU :D HOPE THIS HELPS THE Q
P IS VERY LONG ITS VERY TIME CONSUMING BEWARE OF THE OR QUESTIONS
YOU MAY LOSE TIME HERE THNKS!!!

Panchali Dutta · Accepted Answer

Answer to some of your questions: 6) x âˆ t3 â‡’ v = dx/dt â‡’ v âˆ 3t2 a = dv/dt â‡’ a âˆ 6t a âˆ t Acceleration is directly proportional to time elapsed The body undergoes uniform acceleration The graph of acceleration and time will be a straight line graph 11) Min Number of significant digits = 3 Volume of earth = $\frac{4 π r^{3}}{3}$ =1 082 x 1021 m3 Density of earth = 5 975 x1024/1 082 x 1021 = 5 52 x 103 kg/m3 13 The heat dissipated in a resistance can be determined from the relation : H = I^2Rt/4 2 Cal If the maximum errors in measurement of current, resistance and time are 2%, 1% and 15% respectively what would be the maximum error in the dissipated heat ? $H = I^{2} R t \frac{Δ H}{H} = 2 \frac{Δ I}{I} + \frac{Δ R}{R} + \frac{Δ t}{t}$ =20% 19) $T α p^{a} d^{b} E^{c} [T] = [M L^{- 1} T^{- 2}]^{a} [M L^{- 3}]^{b} [M L^{2} T^{- 2}]^{c} = [M]^{a + b + c} [L]^{- a - 3 b + 2 c} [T]^{- 2 a - 2 c} \Rightarrow a + b + c = 0 a + 3 b - 2 c = 0 2 a + 2 c = - 1 \Rightarrow c = \frac{1}{3}, a = \frac{- 5}{6}, b = \frac{1}{2}$ 24) The net displacement is zero as the cyclist returns to its initial position Average velocity is also zero for the same reason as above Total path travelled = r + Ï€r/2 + r = 2( 1 + Ï€/4) [ as r = 1km] time taken = 10 min = 1/6 hr Average speed = 12 + 3Ï€ = 21 42 m/s Try to solve the rest of the question using the solutions given above as a tool