Question

A ball of mass 20g is initially moving with a velocity of 50 m/s. On applying a constant force on ball for5.0 s, it acquires a velocity of 70 m/s. Calculate : (i) the final momentum of ball (ii) the rate of charge of momentum (iii) the acceleration of ball​

Answer 1

Explanation:

Formula = 0.5 Mark each

Calculation = 0.5 Mark each

Given , mass,

m

=

20

g

=

0.02

k

g

,

initial velocity,

u

=

100

m

s

−

1

time interval,

t

=

0.5

s

and

final velocity,

v

=

150

m

s

−

1

(i) Initial momentum of the ball,

P

1

=

m

a

s

s

×

i

n

i

t

i

a

l

v

e

l

o

c

i

t

y

=

m

u

=

0.02

×

100

=

2

k

g

m

s

−

1

.

(ii) Final momentum of the ball

P

2

=

m

a

s

s

×

f

i

n

a

l

v

e

l

o

c

i

t

y

=

m

v

=

0.02

×

150

=

3

k

g

m

s

−

1

(iii)

R

a

t

e

o

f

c

h

a

n

g

e

o

f

m

o

m

e

n

t

u

m

=

(

P

2

−

P

1

)

t

=

(

3

−

2

)

0.5

=

2.0

k

g

m

s

−

2

=

2.0

N

(iv)

A

c

c

e

l

e

r

a

t

i

o

n

,

a

=

(

v

−

u

)

t

=

(

150

−

100

)

0.5

=

100

m

s

−

2

(v) Force, F

=

m

a

s

s

×

a

c

c

e

l

e

r

a

t

i

o

n

=

0.02

×

100

=

2.0

N