I think it’s d but I’m not sure
Answer:
Explanation:
Given
Force 
one at an angle of 
East of North and another at West of North
Net Force is in North Direction
Forces in horizontal direction will cancel out each other
thus Work done will be by north direction forces
here 
You can’t solve it because you don’t have c in the question
Answer:
2.89 hours
Explanation:
given :
Vo = 72 km/h
Vt = 90 km/h
S = 234 km
find : the time taken (t) = ?
solution :
2.a.s = Vt² - Vo²
2.a.(234) = 90²- 72²
468.a = 8100 - 5184
= 2916
a = 2916/468 = 6.23 km/h²
so,
t = (Vt-Vo) /a
= (90-72)/ 6.23
= 18/ 6.23
= 2.89 hours
Density =mass/volume 120/200 =0.6 g/cm
