David is driving a steady 25.0 m/s when he passes tina, who is sitting in her car at rest. tina begins to accelerate at a steady 2.40 m/s2 at the instant when david passes.

Answer;

= 520.833 m

Explanation and solution;

Assuming D is at 25 m/s; T's acc = 2.4 m/s2  

let time be t and distance be d  

for D,  

25 × t = d  

t = d/25 (1)  

for T,  

u=0  

s= ut + 0.5 at^2  

d = 0 + 0.5 × 2.4 × t^2  

d = 1.2 t^2 (2)  

(1) sub into (2)  

d = 1.2 × [d/25]^2  

d = 0.00192 d^2  

d = 520.833 m

the area between the graph and the t axis

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg