Question

8. In a football match a ball is kicked by a
player with a force of 25N for 0.2 sec and
then by another player with a force of 70 N
for 0.1 sec in the same direction. If the foot
ball gains a velocity of 24 m/s after the two
kicks, the mass of the foot ball is nearly
1) 5kg
2) 10 kg
3) 2.5 kg 4) 0.5 kg​

Answer 1

$\huge\bigstar\underline\pink{Answer}$

★ Impulse = F × ∆t

I1 = 25 * 0.2 =5 N

I2 = 70 × 0.1 =7 N

net impulse = 12N

also, change in momentum = impulse

so,

12 N = M * V

12 N = M * 24

M = 0.5 kg

happy to help !

Answer 2

Answer:

0.5 kg

Explanation:

let mass of ball be m

using F = ma

a1 = 25/m

similarly; a2 = 70/m

usnig equation of motion; v = u + at

initaily ball is at rest

so, after first kick speed of ball be v

v = 0 + 25/m * 0.2

v =  25/m * 0.2

Now, v is inital velocity for another player

v' = v + 70/m*0.1

=> 24 = 25/m * 0.2 + 70/m*0.1 [v' = 24 m/s given]

after solving it ; you get m = 0.5Kg