A car initially travelling 80.7 km/h,(East)slowed down and turned. After executing the turn...?

Question

the car was travelling 57 km/h(South).What was the change in the car's speed (in km/h)?

What's the magnitude of the car's change in velocity ( in km/h)?

Answer 1

Change in speed in East direction = 0
Change in speed in South direction = + 57 Km/hr

Resultant Velocity:
v=dr/dt
= dx/dt

v=vxi+vyj
v=|v|=√(vx2+vy2) = √(80.7)² +(57)² =√6512.49+3249 = √9761= 98.8 Km/hr

Answer 2

Chane in velocity= sqquroot (88.1)^2+(52)^2 =approx. 102.3 km/h