An object of mass 10 Kg moves at a constant speed of 20 m / s. A constant force, that acts for 5 second on the object gives it a speed 2 m / s in opposite direction. The force acting on the object is:

Question

An object of mass 10 Kg moves at a constant speed of 20 m / s. A constant force, that acts for 5 second on the object gives it a speed 2 m / s in opposite direction. The force acting on the object is: (A) 44 N (B) -44 N (C) -20 N (D) 20 N

Tardigrade Admin · Accepted Answer

As we know that, v = u + text at , v =-2 m / s , u =20 m / s (-ve sign) = opposite direction ( v - u /t)= a (-2-20/5)= a ⇒ (-22/5)= a Force = ma =10 × (-22/5)=-44 N

Q. An object of mass $10 K g$ moves at a constant speed of 20 $m / s$ . A constant force, that acts for $5$ second on the object gives it a speed $2 m / s$ in opposite direction. The force acting on the object is:

44 N

-44 N

-20 N

20 N

As we know that,
$v = u + at, v = - 2 m / s, u = 20 m / s$
$(- v e s i g n) =$ opposite direction
$\frac{v - u}{t} = a$
$\frac{- 2 - 20}{5} = a \Rightarrow \frac{- 22}{5} = a$
Force $= ma = 10 \times \frac{- 22}{5} = - 44 N$

Q. An object of mass 10Kg moves at a constant speed of 20 m/s. A constant force, that acts for 5 second on the object gives it a speed 2m/s in opposite direction. The force acting on the object is: