A 1251-kg vehicle takes a 73 m radius turn on a track inclined at 15° to help the vehicle not skid outward. If the vehicle moves at 86 km/h, will it require a frictional force? If necessary, what will be the magnitude and direction of this force?

• A. Need friction force with magnitude 6.3 × 10³ N down the slope, toward the centre of the turn.
• B. Need friction force with magnitude 4.8 × 10³ N down the slope, toward the centre of the turn.
• C. Need friction force with magnitude 6.3 × 10³ N up the slope, outward from the centre of the turn.
• D. Don't need friction.

Answer: (A)