Question
I really really need help with these questins since they took too much time from me.
A crow is flying horizontally with a constant speed of 2.45 m/s when it releases a clam from its beak. The clam lands on the rocky beach 1.80 s later. Consider the moment just before the clam lands. (Neglect air resistance.)
(a) What is its horizontal component of velocity?
(b) What is its vertical component of velocity?
(c) Select all of the following which would apply to your answers for (a) and (b), if the speed of the crow were decreased.
Explain.
Question 2:
A crow is flying horizontally with a constant speed of 2.45 m/s when it releases a clam from its beak. The clam lands on the rocky beach 1.80 s later. Consider the moment just before the clam lands. (Neglect air resistance.) What is its horizontal component of velocity? What is its vertical component of velocity? Select all of the following which would apply to your answers for (a) and (b), if the speed of the crow were decreased. 1-The vertical component would increase. 2-The vertical component would decrease. 3-The horizontal component would increase. 4-The horizontal component would decrease. Explain. Question 2: An electron in a cathode-ray tube is traveling horizontally at 2.06 times times 109 cm/s when deflection plates give it an upward acceleration of 5.37 times 1017 cm/s2. How long does it take for the electron to cover a horizontal distance of 6.34 cm? What is its vertical displacement during this time? Question 3: A second baseman tosses the ball to the first baseman, who catches it at the same level from which it was thrown. The throw is made with an initial speed of 13.0 m/s at an angle of 33.0 degree above the horizontal. (Neglect air resistance.) What is the horizontal component of the ball's velocity just before it is caught? How long is the ball in the air? Last question 4: In baseball, a pitcher can accelerate a 0.15 kg ball from rest to 99 mi/h in a distance of 1.4 m. (a) What is the average force exerted on the ball during the pitch? If the mass of the ball is decreased, is the force required of the pitcher increased, decreased, or unchanged?
Explanation / Answer
1) a) its horizontal component of velocity = 2.45 m/s
b) its vertical component of velocity = 0
c) 3-The horizontal component would decrease.
2) a) time = distrance / speed = 6.34 / 2.06*10^9 = 3.077 * 10^(-9) s
b) its vertical displacement during this time , s = 1/2 * 5.37*10^17 * 3.077*10^(-9) = 8.2617 * 10^8 cm
3) a) the horizontal component of the ball's velocity just before it is caught = 13 * cos(33) = 10.9027 m/s
b) The time = 2 * 13 sin(33) / 9.8 = 1.4449 s
4) a) 44.257^2 = 2 * a * 1.4 ,, So acceleration ,a = 699.529 m/s^2
So , force = mass * acceleration = 0.15 * 699.529 = 104.929 N
b) If the mass of the ball is decreased, then force required of the pitcher decreased