1. If a baseball is thrown 30 m/s backwards from a truck moving forward 50 m/s, how fast will the ball strike the glove of a ground-based catcher?
Where is the catcher?
behind the truck
To solve this problem, you need to consider the relative velocities of the baseball and the catcher's glove. Let's break down the problem step by step:
1. Determine the relative velocity of the baseball with respect to the truck:
Baseball velocity = -30 m/s (negative sign indicates the backward direction)
Truck velocity = 50 m/s (positive sign indicates the forward direction)
Relative velocity = Baseball velocity - Truck velocity
= -30 m/s - 50 m/s
= -80 m/s
Here, the negative sign implies that the baseball is moving in the opposite direction of the truck.
2. Determine the speed of the baseball relative to the ground:
Speed of the truck = 50 m/s
Speed of the baseball relative to ground = Speed of the truck + Relative velocity
= 50 m/s + (-80 m/s)
= -30 m/s
Again, the negative sign indicates that the baseball is moving backward relative to the ground.
3. Assuming the catcher's glove is stationary on the ground, the velocity of the baseball when it strikes the glove will be equal to its speed relative to the ground:
Speed of the baseball when it strikes the glove = -30 m/s
Therefore, the baseball will strike the glove with a speed of 30 m/s in the backward direction.