# I have some questions about physics? 1. A baseball is moving at 31 m/s East when it is struck by the bat and moves off in the opposite direction at 35 m/s. If the impact lasted 0.010s, find the...

# I have some questions about physics?

1. A baseball is moving at 31 m/s East when it is struck by the bat and moves off in the opposite direction at 35 m/s. If the impact lasted 0.010s, find the baseball's acceleration in m/s^2 during the impact.

2. A shopping cart given an initial velocity at 2.0 m/s East undergoes a constant acceleration of 3.0 m/s^2. What is the cart's displacement after the first 5.0s of its motion?

2. A shopping cart given an initial velocity at 2.0 m/s East undergoes a constant acceleration of 3.0 m/s^2. What is the cart's displacement after the first 5.0s of its motion?

3. An airplane must have a velocity of 50 m/s in order to take off. What must the airplane's acceleration be if it is to take off from a runway 0.45 km long?

4. 2 part question: Amanda is running away from Ben. Both are travelling at a constant speed. Amanda's speed is 1.5 m/s and Ben's speed is 2.2 m/s. Amanda gets a 30s head start.

a. Determine how long it takes for Ben to catch up to Amanda.

b. Determine the distance traveled when Ben catches Amanda.

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### 1 Answer

2.

The formula for the displacement is

`d=v_0t + (at^2)/2` , where `v_0` is the initial velocity, a is the acceleration and t is the time elapsed from the beginning of the motion.

So after t = 5 s, assuming acceleration is in the same direction as the initial velocity (even though it is not really stated in the problem), the displacement will be

`d=2*5 + (3*5^2)/2 = 10+37.5 = 47.5` meters.

**The displacement after 5 seconds of motion will be **

**d = 47.5 meters.**