Answer: It takes 2.85 seconds.
Explanation: according to the question, the kinematics equation for vertical motion is
y₀ is the initial postion and equals 0 because it is fired at ground level;
v₀ is the initial speed and eqauls 14m/s;
g is gravity and it is 9.8m/s²;
y(t) is the final position and equals 0 because it is when the pumpkin hits the ground;
Rewriting the equation, we have:
0 + 14t - 
= 0
14t - 4.9t² = 0
t(14 - 4.9t) = 0
For this equation to be zero,
t = 0 or
14 - 4.9t = 0
- 4.9t = - 14
t = 
t = 2.86
It takes 2.86 seconds for the pumpkin to hit the ground.
Answer:
The tension increases by a factor of 8
Explanation:
We know that the tension, T in the string equals the centripetal force on the ball. So
T = mrω² = mr(2πf)² = 4mrπ²f² where m = mass of ball, r = radius of circle and f = frequency of rotation
If the radius and frequency are doubled, then r = 2r and f = 2f. So, the new tension is T' = 4mr'π²f'² = 4m(2r)π²(2f)² = 4 × 2 × 4mrπ²f² = 8T
Since T' = 8T,
So T'/T = 8.
So the tension increases by a factor of 8
Answer:
12 km/h
Explanation:
Average Speed = Distance / Time (or rate)
Pick a point on the graph for Ian and plug in values.
For example, 20 minutes -> 4km
Hence, Average speed = 4km ÷ 20 minutes = 0.2 km/min
0.2 km/min × 60 = 12 km/h
F=ma
F=125 N
m= 50 kg
125=50a
a=2.5 m/s^2
