21. A body is at rest at x = 0, At t = 0, it starts...

Transcribed Image Text:

21. A body is at rest at x = 0, At t = 0, it starts moving in the positive x-direction with a constant acceleration. At the same instant another body passes through x = 0 moving in the positive x-direction with a constant speed. The position of the first body is given by x,(t) and the position of the second body is x,(t) 27. A projectile is given an initial velocity of (î +2j) mls, where i is along the ground and i is along the vertical. If g=10 m/s, the equation of its trajeclory is %3D %3D (2013) 1) y=x-5x² 2) y=2x-5x² 3) 4y=2x-5x² 4) 4y=2x-25x² after the same time interval. Which of the 28. From a tower of height H, a particle is thrown vertically upwards with a speed u. The time taken by the particle to hit the ground, is n times that taken by it to reach the highest point following graphs correctly describes (x,-x,) as a function of time 't'? (2008) (X1, X2 (x17 X2 1) 2) of its path. The relation between H, u and (2014) t n is : (X1, X2 (X1r X2 1) gH = (n – 2)u² 2) 2gH = n²u² | 3) gH = (n – 2)u² 4) 2gH = nu²(n- 2) %3D 4) 29. Two stones are thrown up simultaneously from the edge of a cliff 240m high with initial speed of 10m/s and 40m/s respectively. Which of the following graph best represents the time variation of relative position of the second t *22. A particle has an initial velocity 3î+4j and an acceleration of 0.4i + 0.3j. Its speed after (2009) 10s is 1) 10 units 2) 7/2 units stone with respect to the first ? (Assume stones do not rebound after hitting the ground and neglect air resistance, take g = 10m/s²) The figures are schematic and not drawn to (2015) 3) 7 units 4) 8.5 units 23. A particle is moving with velocity v = K(yi+ xj), where K is a constant. The (2010) scale general equation for its path is 1) y = x² + constant 2) y = x +constant y" = x + constant xy = constant (y2-Y1)m 240 (y2-Yi)m 240 2) 24. A water fountain on the ground sprinkles water all around it. If the speed of water coming out of the foutain is v, the total area around the fountain that gets wet is v² 2) T 1) (S) 12 12 (2011) 4 240 (Y2-y1)m T V4 1) 240+(2-Yı)m 3) T- 4) T 3) 4) 12 t (S) 12 25. An object, moving with a speed of 6.25 m/s, is 30. A body is thrown vertically upwards. Which one of the following graphs correctly represent the velocity vs time? dv '=-2.,5v. dt declerated at a rate given by (2017): where v is the instantaneous speed. The time taken by the object, to come to rest, would be (2011) 2) 1) 4s 2) 8s 3) 1s 4) 2s 26. A boy can throw a stone up to a maximum height of 10m. The maximum horizontal distance that the boy can throw the same stone (2012) 3) 10/2m 4) 20m 3) 4) up to will be 1) 20/2m 2) 10m 7 21. A body is at rest at x = 0, At t = 0, it starts moving in the positive x-direction with a constant acceleration. At the same instant another body passes through x = 0 moving in the positive x-direction with a constant speed. The position of the first body is given by x,(t) and the position of the second body is x,(t) 27. A projectile is given an initial velocity of (î +2j) mls, where i is along the ground and i is along the vertical. If g=10 m/s, the equation of its trajeclory is %3D %3D (2013) 1) y=x-5x² 2) y=2x-5x² 3) 4y=2x-5x² 4) 4y=2x-25x² after the same time interval. Which of the 28. From a tower of height H, a particle is thrown vertically upwards with a speed u. The time taken by the particle to hit the ground, is n times that taken by it to reach the highest point following graphs correctly describes (x,-x,) as a function of time 't'? (2008) (X1, X2 (x17 X2 1) 2) of its path. The relation between H, u and (2014) t n is : (X1, X2 (X1r X2 1) gH = (n – 2)u² 2) 2gH = n²u² | 3) gH = (n – 2)u² 4) 2gH = nu²(n- 2) %3D 4) 29. Two stones are thrown up simultaneously from the edge of a cliff 240m high with initial speed of 10m/s and 40m/s respectively. Which of the following graph best represents the time variation of relative position of the second t *22. A particle has an initial velocity 3î+4j and an acceleration of 0.4i + 0.3j. Its speed after (2009) 10s is 1) 10 units 2) 7/2 units stone with respect to the first ? (Assume stones do not rebound after hitting the ground and neglect air resistance, take g = 10m/s²) The figures are schematic and not drawn to (2015) 3) 7 units 4) 8.5 units 23. A particle is moving with velocity v = K(yi+ xj), where K is a constant. The (2010) scale general equation for its path is 1) y = x² + constant 2) y = x +constant y" = x + constant xy = constant (y2-Y1)m 240 (y2-Yi)m 240 2) 24. A water fountain on the ground sprinkles water all around it. If the speed of water coming out of the foutain is v, the total area around the fountain that gets wet is v² 2) T 1) (S) 12 12 (2011) 4 240 (Y2-y1)m T V4 1) 240+(2-Yı)m 3) T- 4) T 3) 4) 12 t (S) 12 25. An object, moving with a speed of 6.25 m/s, is 30. A body is thrown vertically upwards. Which one of the following graphs correctly represent the velocity vs time? dv '=-2.,5v. dt declerated at a rate given by (2017): where v is the instantaneous speed. The time taken by the object, to come to rest, would be (2011) 2) 1) 4s 2) 8s 3) 1s 4) 2s 26. A boy can throw a stone up to a maximum height of 10m. The maximum horizontal distance that the boy can throw the same stone (2012) 3) 10/2m 4) 20m 3) 4) up to will be 1) 20/2m 2) 10m 7

Answer rating: 100% (QA)

21 Option 4 is correct Explaination Relative distance at any point S1t12at2 S2tVt S1S212at2vt 22 Opt... View the full answer