consider the velocity towards the pitcher as positive
m = mass of the baseball = 0.145 kg 
v₀ = initial velocity of the baseball = - 39 m/s 
v = final velocity of the baseball = 52 m/s 
t = time of contact = 3 x 10⁻³ sec 
F = average force between bat and ball 
Using impulse-change in momentum equation 
F t = m (v - v₀ )
F (3 x 10⁻³) = (0.145) (52 - (- 39))
F = 4398.33 N 
 
        
             
        
        
        
Answer:
Because cosmic disaster are so vast, astronomers use light-years as their unit of distance. One light-year is defined as <u>the distance a beam of light travels in one year</u>. The nearest star is a little more than <u>4.37 light-years</u> away from us. When we see light from a galaxy 2 million light-years away, it has taken<u> 2 million Earth years</u> to reach us. Light from the Sun takes <u>approximately 8.4269 minutes</u> to reach us
Explanation:
i) One light-year is defined as the distance a light beam travels in a time of one Earth year. One light year is equivalent to 6 × 10¹² miles or 9.7 × 10¹² km
ii) The distance to the nearest star =  4.37 light-years
iii) When a star located in a galaxy that is 2.3 million light years away is seen, it has taken 2.3 million light years to reach us
iv) The distance of the Sun to the Earth = 151.58 million kilometers
The speed of light, c = 299792.458 km/s
The time it will take light to reach us from the Sun, 't', is given as follows;
t = 151.58 × 10⁶ km/(299792.458 km/s) ≈ 8.4269 minutes.