Question

1. A car with an initial velocity of 5m/s acceaccelerates uniformly at 3 metre per second square until it reaches a velocity of 23 m per second calculate the time taken and the distance travel during this acceleration?
2 . a train starts from rest and moves with a uniform acceleration of x metre per second square for 5 minutes determine the value of x if it covers a distance of 5.8 km during the journey

3. a stone thrown up is caught by the thrower after 6 seconds how high did it go and where was it 4 seconds after start??


Thank you
Please show solvings​

Answer 1

Explanation:

here, u = 5m/s,a = 3m/s2, v = 23m/s, t = ?, s = ?

v = u+at

23 = 5 + 3t

t = 23- 5/3 = 18/3 = 6 sec

s= ut + 1/2 at ^2

s = 5 * 6 + 1/2 * 3 * (6)^2

s = 30 + 1/2 * 3 * 36

s = 30 + 18 * 3

s= 30 + 54 = 84 m

here, u = 0, a = x, t = 5min = 300 sec, s= 5.8km = 5800m

s = ut + 1/2 at^2

5800 = 0 * 300 + 1/2 * x * (300)^2

5800 = 1/2 * x * 90000

5800= 45000 x

x = 5800/45000

x = 0.12m/sec^2

here, v = 0, t = 6sec, s = ?, a = - 9.8m/s2

s = UT + 1/2 at ^2

s = 29.4 * 3 + 1/2 * - 9.8 * (3)^2

s= 88.2 - 44.1

s= 44.1 m

s = ut + 1/2 at ^2

s = 0 * 1 + 1*2 * 9.8 * (1)^2

s = 4.9m

hope it helps you