The displacement of a body is given by the equation s=4t-8. What would be its velocity at the end of 4 seconds?
t = 4sec s = 4t-8 The displacement-time equation is given by, s = 4t-8 differentiating wrt t we have, v=ds/st = 4 As the derivative contains a constant value, therefore, the velocity of the body would remain constant which is 4m/sec.
A can complete a task in 10 days. B can complete the same task in 5 days. How many days would it take the task to complete if both A and B work together?
Let the amount of work to be completed be 100% percentage of work completed by A in one day = 100/10 = 10% percentage of work completed by B in one day = 100/5 = 20% Together the percentage of work completed by both A and B = 10+20 = 30% work completed in one day = 30% Then the no days it would take to complete 100% of work is = 100/30 = 3.33 Hence the no days it would take the task to complete would be approximately 4 days if both A and B work together.
A ball having initial velocity 0 is dropped from a height of 18 m cliff. what would be the velocity of the ball as soon it reaches the ground.
u = 0 v = ? s = 18 g = 9.8m/sec2 formula V2 – U2 = 2as substituting the values we have, v2 = 2as + u2. v2 = 2*9.8*18 + 0 v = 18.78m/sec.