Answered

A particle moving in a straight line with uniform deceleration has a velocity of 40ms¯¹ at a point P 20ms¯¹ at a point Q and comes to rest at a point R where QR=50m Calculate the I. Distance PQ Ii. Time taken to cover PQ Iii. Time taken to cover PR​



Answer :

MathPhys

Answer:

I. 150 m

II. 5 s

III. 10 s

Explanation:

For objects with constant acceleration, we can use a set of kinematic equations known as SUVAT, where:
S = displacement (change in position)
U = initial velocity
V = final velocity
A = acceleration
T = time

First, use points Q and R to find the acceleration. Given:

s = 50 m

u = 20 m/s

v = 0 m/s

Find a:

v² = u² + 2as

0² = 20² + 2a (50)

a = -4 m/s²

I. Given between P and Q:

u = 40 m/s

v = 20 m/s

a = -4 m/s²

Find s:

v² = u² + 2as

20² = 40² + 2(-4)s

s = 150 m

II. Find t:

v = u + at

20 = 40 + (-4)t

t = 5 s

III. Given from P to R:

u = 40 m/s

v = 0 m/s

a = -4 m/s²

Find t:

v = u + at

0 = 40 + (-4)t

t = 10 s

Other Questions