Question

A car travels around a curve with constant speed. The correct statement from the following is the car has an acceleration directed inward toward the center of the curve. the velocity of the car is constant. the car has an acceleration direction outward from the center of the curve. the car has zero acceleration. the car has an acceleration directed in the instantaneous direction of the velocity vector. A ball is whirled on the end of a string in a horizontal circle at constant speed. Suddenly string breaks. Immediately after the string breaks, the ball will have a horizontal velocity away from the center of the circle have a horizontal velocity that is tangential to the circle. have a horizontal velocity toward the center of the circle. have a horizontal velocity partly in away from the center of the circle and partly tangent to the circle have no horizontal velocity. On a two-lane highway (not divided), a car headed north experiences a centripetal acceleration directed toward the west. Simultaneously, a truck passes the car, headed south in the lane. The direction of the centripetal acceleration on the truck is west east. north. south. A ball at the end of a string is swinging as a simple pendulum. Assuming no loss in energy due to friction, we can say for the ball that the potential energy is maximum at each end of the motion. the mechanical energy changes and is maximum where the kinetic energy is minimum. the mechanical energy changes and is maximum where the kinetic energy is maximum. the kinetic energy does not change but the potential energy does. On a frictionless tabletop, a force is applied to an object: the object's velocity is horizontal and the force is perpendicular to the tabletop. Which of the following is true? The applied force is friction. The total energy of the object does not change. There cannot be more than one force on the object. The force does work on the object.

please ansa all

Answer 1

The velocity of the car is along the $\hat{\phi}$

So the accelaration is along $\dot{\hat{\phi}}$

so,

$\dot{\hat{\phi}}=-\dot{\phi}\hat{r}$

So the direction of accelaration is along $-\hat{r}$ direction.

The answer is option (A)