Answer:
D = 4 m
Step-by-step explanation:
Speed of cart in air track v₁ = 0.5 m/s
Speed of cart moved when air is turned off v₂= 1 m/s
The distance travelled by the cart is d₁ = 1 m
Work done (W) = F x d
Work done is equal to the kinetic energy
F x d = 1/2mv²
velocity is directly proportional to distance
therefore,
v₁²/ v₂² = d₁ / d₂
d₂ = d₁v₂² / v₁²
= 1 m x (1 m /s)² / (0.5 m/s)²
= 4 m