If you throw a baseball straight up, what is its velocity at the highest point?

Which of the following statements are true?I. If a car is traveling eastward and slowing down its acceleration is westward.II. When a ball is tossed straight up, at the highest point of its path, the velocity is zero but the acceleration is non-zero.III. The average speed of an object is always equal to the magnitude of its average velocity

For projectile motion problems, the horizontal and vertical components of the motion of a projectile can be analyzed separately. Which of the following is TRUE about the horizontal component of its motion?a. The horizontal component of the acceleration is constant and is equal to -9.81 m/s^2b. The motion is uniformc. The horizontal component of the velocity varies with positiond. The motion is uniformly accelerated

On a one lane road, a person driving a car at v1 = 54 mi/h suddenly notices a truck 0.65 mi in front of him. That truck is moving in the same direction at v2 = 35 mi/h. In order to avoid a collision, the person has to reduce the speed of his car tov2 during time interval Δt. The smallest magnitude of acceleration required for the car to avoid a collision is a. During this problem, assume the direction of motion of the car is the positive direction. Refer to the figure. Part (a) Enter an expression, in terms of defined quantities, for the distance, Δx2, traveled by the truck during the time interval Δt. Part (b) Enter an expression for the distance, Δx1, traveled by the car in terms of v1, v2 and a. Part (c) Enter an expression for the acceleration of the car, a, in terms of v1, v2, and Δt.

On a one lane road, a person driving a car at v1 = 54 mi/h suddenly notices a truck 0.65 mi in front of him. That truck is moving in the same direction at v2 = 35 mi/h. In order to avoid a collision, the person has to reduce the speed of his car tov2 during time interval Δt. The smallest magnitude of acceleration required for the car to avoid a collision is a. During this problem, assume the direction of motion of the car is the positive direction. Refer to the figure. The expression, in terms of defined quantities, for the distance, Δx2, traveled by the truck during the time interval Δt is deltax2= v2 times delta t. Part (b) Enter an expression for the distance, Δx1, traveled by the car in terms of v1, v2 and a. Part (c) Enter an expression for the acceleration of the car, a, in terms of v1, v2, and Δt. (d) enter an expression for delta x1 in terms of delta x2 and d when the drive just barely avoids collision.

Can the velocity of an object be negative when its acceleration is positive? What about vice versa? If yes, give examples in each case

On a one lane road, a person driving a car at v1 = 58 mi/h suddenly notices a truck 1.1 mi in front of him. That truck is moving in the same direction at v2 = 35 mi/h. In order to avoid a collision, the person has to reduce the speed of his car to v2 during time interval Δt. The smallest magnitude of acceleration required for the car to avoid a collision is a. During this problem, assume the direction of motion of the car is the positive direction.  1. Use the expressions you entered in parts (c) and (f) and enter an expression for a in terms of d, v1, and v2.  a = ( v2 - v1 )/Δt   Δt = ( 2 ) ( d )/( v1 - v2 ) 2. Calculate the value of a in meters per second squared.