Description : A rocket is fired vertically from the ground with a resultant vertical acceleration of 10 m/sec the fuel is finished in one minute and it continues to move up. The maximum height reached will be a.2 km b.20 km c.36 km d.10 km e.80 km
Last Answer : a. 2 km
Description : A particle starts from rest and moves in a straight line whose equation of motion is given by S = 2t3 - t2 - 1. The acceleration of the particle after one sec will be a.6 m/sec2 b.4 m/sec2 c.12 m/sec2 d.10 m/sec2 e.8 m/sec2
Last Answer : d. 10 m/sec2
Description : In which case power required would be more a.In lifting up a weight of 100 kg at a velocity of 3 m/sec but accelerating upwards at 0.5 m/sec b.In lowering a weight of 100 kg along an a inclined plane ... speed of 3 m/sec e.In lowering the weight at a velocity of 3 m/sec and acceleration of 1 m/sec2
Last Answer : a. In lifting up a weight of 100 kg at a velocity of 3 m/sec but accelerating upwards at 0.5 m/sec
Description : Critical speed of rotation, N (in rps - rotation per second) of a trammel is equal to (where, g = acceleration due to gravity = 9.81 m/sec 2 and, r = radius of trammel, metre.) (A) (1/2π). √(g/r) (B) (1/π). √(g/r) (C) ½ √(g/r) (D) 2π. √(g/r)
Last Answer : (A) (1/2π). √(g/r)
Description : An object moves along a straight line with an acceleration of 2 m/s2. If its initial speed is 10 m/s, what will be its speed 2 s later? -Science
Last Answer : u=10 m/s,t=2 s, a=2 m/s2 v=u+atv=u+at v=10+2×2=14v=10+2×2=14 m/s
Description : An object dropped from a cliff falls with a constant acceleration of 10 m/s2. Find its speed 5 s after it was dropped. -Science
Last Answer : v=u+atv=u+at u=0u=0 v=10×5=50m/sv=10×5=50m/s
Description : A train crosses a platform and a scooter standing on the platform in 20 seconds, 12seconds respectively.What is the length of the platform if the speed of the train is 25 km/hr? A) 55.8 m B) 75m C) 124m D) 68.5m
Last Answer : Answer: A Explanation: Given that, The speed of the train = 25km/hr = 25x 5/18 m/sec = 125/18 m/sec The train crosses a scooter in 12 seconds. Then, Length of the train = 125/18*12= 83.33 Now, ... 18(X +83.3)= 2500 18X=1000.6 X=55.58 m Hence the platform is 55.58 m long.
Description : A cage weighing 200 kg is lowered down a mine shaft with uniform acceleration. In the first 5 sec the cage reaches a depth of 20 m. The tension in the cord lowering the cage would be a.836 kg b.167.2 kg c.100 kg d.41.8 kg e.200 kg
Last Answer : b. 167.2 kg
Description : A train accelerates from 36 km/h to 54 km/h in 10 sec. (i) Acceleration (ii) The distance travelled by car. -Science
Last Answer : a. Acceleration is given by a=ΔvΔta=ΔvΔt Δv=54−36=18km/hr=18×10003600m/s=5m/sΔv=54−36=18km/hr=18×10003600m/s=5m/s So a=.5 m/s2 b. Distance is given by S=ut+12at2S=ut+12at2 Now u=36 km/hr =10m/s s=10×10+12×.5×102s=10×10+12×.5×102 So s=125m
Description : If a train crosses a tree in 24 seconds while travelling at a speed of 90km/hr, then in how much time will the train cross a telegraph post of length 1200m at same speed? A) 26 sec B) 48 sec C) 72 sec D) 38 sec
Last Answer : ANSWER:C Explanation: Speed of the train = 90 km/hr Converting the speed into m/sec 90 km/hr = (90* 5/18)m/s = 25m/s length of the train = distance travelled we know distance = speed * ... Time = distance / speed = ( 1800/25) sec = 72 seconds Hence the required answer is 72 seconds
Description : Two waves, each of amplitude 1.5 mm and frequency 10 Hz, are travelling in opposite direction with a speed of 20 mm/s. The distance in mm between adjacent nodes is : (1) 1.0 (2) 1.2 (3) 1.5 (4) 2.0
Last Answer : (1) 1.0 Explanation: Since the amplitudes, frequency and the speed of both the waves are in same, hence the wavelength of the composite wave will be the same as the single wave.
Last Answer : 2mm
Description : Two trains of equal lengths take 10 seconds and 15 seconds respectively to cross a telegraph post. If the length of each train be 120 metres, in what time (in seconds) will they cross each other travelling in opposite direction? A.12 sec B.18 sec C.14 sec D.25 sec E.None of these
Last Answer : Answer – A (12 sec) Explanation – Speed of the first train = [120 / 10] m/sec = 12 m/sec. Speed of the second train = [120 / 15] m/sec = 8 m/sec. Relative speed = (12 + 8) = m/sec = 20 m/sec. ∴ Required time = (120 + 120) / 20 secc = 12 sec
Description : A body moves, from rest with a constant acceleration of 5 m per sec. The distance covered in 5 sec is most nearly (A) 38 m (B) 62.5 m (C) 96 m (D) 124 m
Last Answer : (B) 62.5 m
Description : An electron moving with a velocity of 5 10 3 m / s enters into a uniform electric field and acquires a uniform acceleration of 10 3 m / s 2 in the direction of initial velocity. i. ... which electron velocity will be doubled.? ii. How much distance electron would cover in this time.? -Science
Last Answer : Given u=5×103m/su=5×103m/s , a=103m/s2a=103m/s2, v=2u=104v=2u=104 m/s i.Using v=u+atv=u+at 104=5×103+103t104=5×103+103t or t=5 sec ii. Using s=ut+12at2s=ut+12at2 s=5×103×5+12×103×52s=5×103×5+12×103×52 =37.5×103m=37.5×103m
Description : A marble of mass 2m travelling at 6 cm/s is directly followed by another marble of mass m with double speed.
Last Answer : A marble of mass 2m travelling at 6 cm/s is directly followed by another marble of mass m ... of the two. Calculate the coefficient of restitution.
Description : An electron is travelling at right angles to a uniform magnetic field of flux density 1.2 mT with a speed of 8 × 106 m s-1, the radius of circular path followed by electron is A. 3.8 cm B. 3.7 cm C. 3.6 cm D. 3.5 cm
Last Answer : 3.8 cm
Description : The frequency of a wave travelling at a speed of 500 ms-1 is 25 Hz. Its time period will be ______. (i) 20 s (ii) 0.05 s (iii) 25 s (iv) 0.04 s
Last Answer : (iv) 0.04 s
Description : A train travelling at 20 m s-1 accelerates at 0.5 m s-2 for 30 s, the distance travelled by train is A. 825 m B. 700 m C. 650 m D. 600 m
Last Answer : 825 m
Description : An object travels from a fixed position 5 seconds to start the journey. After 20 m / s. Velocity is. Next 10 sec. How far will it cover ?
Last Answer : The distance covered by the object in the next 10 seconds s = vt s = 20 × 10 = 200m
Description : Stopping distance of vehicles : When brakes are applied to a moving vehicle, the distance it travels before stopping is called stopping distance. It is an important factor for road safety and depends on ... the brake with the deceleration of 5m/s2. Find the stopping distance of the car -Science
Last Answer : Here u=72 km/hr = 72×10003600m/s=2072×10003600m/s=20 m/s , v=0 a= -5 m/s2 Now using the relation v2=u2+2asv2=u2+2as 0=(20)2+2×(−5)×s0=(20)2+2×(−5)×s s=40ms=40m
Description : The velocity, time graph of two bodies A and B travelling along the +x direction are given in the fi gure.(a) Are the bodies moving with uniform acceleration ? (b) Which body is moving with greater acceleration ? Give reasons. -Biology
Last Answer : The acceleration is given by the slope of velocity-time graph. Slope of body-A > Slope of body-B as it forms a greater angle with time axis than body B. Thus, body A moves with higher acceleration
Description : A car starts from rest and moves on a straight road with a uniform acceleration of 10 m/s2 for the first 10 s. During the next 10 s, the car move s with the velocity it has attained. What is the total distance covered by the car in 20 s? (a) 500 m (b) 1000 m (c) 1,500 m (d) 2,000 m
Last Answer : Ans:(c)
Description : A train 170 m long is running at a speed of 22.5 km/hr. what time will it take to cross a 80m long bridge? A) 20 sec B) 40 sec C) 15 sec D) 30sec
Last Answer : ANSWER:B Explanation: Length of the train = 170 m Length of the bridge = 80 m Therefore, length of the train + length of the bridge = (170 + 80) m = 250m Speed of the train = 22.5 km/hr Speed ... .25m/sec Therefore, time taken by the train to cross the bridge = 250 m/6.25 m/sec. = 40 seconds.
Description : A roller coaster reaches a velocity of 20 m/s at a location where the radius of curvature is 40 m. Calculate the acceleration in m/s2? a.10 b.9 c.11 d.8 e.107 dynes
Last Answer : a. 10
Description : If a spinster staring from rest has acceleration of 5 m s-2 during 1st 2.0 s of race then her velocity after 2 s is A. 20 m s-1 B. 10 m s-1 C. 15 m s-1 D. 5 m s-1
Last Answer : 10 m s-1
Description : Ganesh is travelling on his motorbike and has calculated to reach golden temple at 8 p.m if he travels at 30 km/hr; he will reach there at 6 p.m if he travels at 45 km/hr. At what speed must he travel to reach the golden temple at 7 p.m? a) 36 b) 46 c) 32 d) 30
Last Answer : A Let the distance travelled be x km x/30 – x/45 = 2 (3x – 2x) / 90 = 2 x/90 = 2 x = 180km Time taken to travel 180 km at 30 km/hr = 180 / 30 = 6 hrs So ganesh started 6 hrs before 8 pm That is 2 pm Required speed = distance / time =(180/5) =36 km/hr
Description : A boy sitting in a train which is travelling at 25 km/hr observes that a goods train travelling in opposite direction, takes 4.5 seconds to pass him. If the train is 140 m long, find its speed. A) 77km/hr B) 79km/hr C) 87km/hr D) 89km/hr
Last Answer : ANSWER : C Explanation: Relative speed = distance / time = (140 / 4.5) m/s = 31.11 m/s Convert m/s into km/hr 31.11 m/s = (31.11 * 18 / 50 km/hr = (560 / 5) km/hr = ... train (by sitting) = (112 - 25) km/hr = 87 km/hr Therefore the speed of goods train is 87 km/hr.
Description : A particle experiences constant acceleration for 20 seconds after starting from rest. If it travels a distance D1 in the first 10 seconds and distance D2 in the next 10 seconds then, (a) D2 = D1 (b) D2 = 2D1 (c) D2 = 3D1 (d) D2 = 4D1 -Science
Last Answer : (c) is the answer
Description : Kishore is travelling on his bike and has calculated to reach point P at 4 pm if he travels at 20 kmph. He will reach there at 12 noon if he travels at 30 kmph. At what speed must he travel to reach P at 2 pm? a) 18 kmph b) 12 kmph c) 24 kmph d) 16 kmph
Last Answer : C Let the distance be x km Travelling at 20 kmph, Kishore will reach point P at 4pm. Travelling at 30 kmph, Kishore will reach point P at 12noon. Therefore, time taken when travelling at 20km - ... his travelling time must be (12-2)=10 hours Hence, required speed =240/10=24 kmph
Description : A rotary system has a damping coefficient of 40 N-m-sec/rad. The damping torque at a velocity of 2 rad/s, will be A) 20 N-m B) 40 N-m C) 80 N-m D) 100 N-m
Last Answer : C) 80 N-m
Description : The speed of a motor car changes from 18 km/h to 72 km/h in 5 s. Its acceleration is (a) 6 m/s2 (b) 5 m/s2 (c) 4 m/s2 (d) 3 m/s2
Last Answer : Ans:(d)
Description : What is a cars acceleration if if increases it and speed from 5 ms to 20 ms in 3 s?
Last Answer : Need answer
Description : Acceleration of train when it is moving steadily from 4.0 m s-1 to 20 m s-1 in 100 s is A. 1 m s-2 B. 2 m s-2 C. 0.16 m s-2 D. 3 m s-2
Last Answer : 0.16 m s-2
Description : A stone of wight 100 kg is thrown vertically upwards by a man of height y = 1.8 m with an initial velocity of 20 m/sec. The maximum height to which it will rise would be a.22.2 m b.26 m c.15.1 m d.20.2 m e.10 m
Last Answer : a. 22.2 m
Description : A block of weight 20 kg slides with an initial velocity of 2 m sec down an inclined plane on to a spring of stiffness 10 kg/cm. If the co--efficient of friction is 0.2, angle ? = 30 the ratio of ... be a.More than one b.One c.Less than one d.Depends on the stiffness of spring e.None of the above
Last Answer : a. More than one
Description : The time required to stop a car moving with a velocity 20 m/sec within a distance of 40 m is equal to a.8 sec b.2 sec c.4 sec d.10 sec e.6 sec
Last Answer : c. 4 sec
Description : A jet of water of cross-sectional area 20 sq. cm impinges on a plate at an angle of 60? with a velocity of 10 m/sec. Neglecting the friction between the jet and plate (density of water 1000/9.81 kgm-1 sec2 per cubic meter), the ... a.15 - 20 kg b.20 - 25 kg c.5 - 10 kg d.25 - 30 kg e.10 - 15 kg
Last Answer : a. 15 - 20 kg
Description : In sewers the velocity of flow should not be A. More than the self-cleansing velocity B. Less than the self-cleansing velocity C. Less than 10 m/sec D. More than 20 m/sec
Last Answer : ANS: B
Description : In a 2-mass 3 spring vibrating system the two masses each are of 9.8 kg coupling spring is having a stiffness of 3430 N/m whereas the other two springs have each a stiffness of 8820 N/m. The two natural frequencies in rad /sec are A) 10 & 20 B) 20 & 30 C) 30 & 40D) 40 & 50
Last Answer : C) 30 & 40
Description : A pipe of I.D. 4 m is bifurcated into two pipes of I.D. 2 m each. If the average velocity of water flowing through the main pipe is 5 m/sec, the average velocity through the bifurcated pipes is (A) 20 m/sec (B) 10 m/sec (C) 5 √2 m/sec (D) 5 m/sec
Last Answer : (B) 10 m/sec
Description : How much work is done to increase a 20kg scooter and speed from 10ms to 20ms?
Last Answer : 3000 J
Description : How to get a little more speed and power out of a Chinese made scooter.?
Last Answer : With the explosion of fuel prices all over the world, it is nowonder so many people have scrambled to purchase affordable Chinesemade 50cc scooters. The issue with many of these GY6 50cc ... can yield significant gains in both power and speed.Modifications such as tuned exhaust systems can dramatic
Description : kajal rides his scooter 14km at an average speed of 16 km/hr and again travels 16km at an average speed of 14 km/hr. What is her average speed for the entire trip approximately? a) 15.36 km/hr b) 17.46 km/hr c) 13.56 km/hr d) 14.86 km/hr
Last Answer : D Total distance travelled =14+16=30Km Time taken to travel 14 km at an average speed of 16 km/hr =14/16=7/8 Hr Time taken to travel 16 km at an average speed of 14 km/hr =16/14=8/7 hr Total time taken = ... /Total time taken =30/(7/8+8/7) =30/(113/56) =30*56/113=1680/113 =14.86 km/hr
Description : The angular acceleration of a flywheel decreases uniformly from 8 rad/sec2 to 2 rad sec2 in 6 sec at which time its angular velocity is 42 rad/sec. The initial angular velocity was a.12 rad/sec b.24 rad/sec c.30 rad/sec d.3 rad/sec e.6 rad/sec
Last Answer : a. 12 rad/sec
Description : The number of revolutions through which a pulley will rotate from rest if its angular acceleration is increased uniformly from zero to 12 rad per sec2 during 4 sec and then uniformly decreased to 0 rad per sec2 during the next 3 sec would be a.46.4 b.26.74 c.11.6 d.3.2 e.17.7
Last Answer : b. 26.74
Description : Find the mean free path of an electron travelling at a speed of 18m/s in 2 seconds. a) 9 b) 36 c) 0.11 d) 4.5
Last Answer : b) 36
Description : Calculate the convection current when electron density of 200 units is travelling at a speed of 12m/s. a) 16.67 b) 2400 c) 2880 d) 0.0
Last Answer : b) 2400
Description : A train starts from rest and accelerate uniformly at the rate of 5 m/s2 for 5 sec. Calculate the velocity of train in 5 sec. -Science
Last Answer : Here u=0 ,a= 5m/s2 ,t= 5 sec,v=? Now v=u+atv=u+at v=0+5×5=25v=0+5×5=25 m/s
Description : A travelling wave passes a point of observation where the time interval between successive crests is 0.2 s. Which of the following is then true? (a) The wavelength is 5 m (b) The wavelength is 0.2 m (c) The velocity of propagation is 5 m/s (d) The frequency of 5 Hz.