Question

b) which letter shows the ball when it has the maximum gravitational potential energy?
c) which letter shows the ball when it has the least gravitational potential energy?
d) why is point g slightly lower than point a? in other words, why couldnt the ball go back to the same height at which it started?

1. use the diagram below to answer the next set of questions

a) at what letter does the ball have the greatest moving kinetic energy?
b) which letter shows the ball when it has the maximum grav. potential energy?
c) which letter shows the ball when it has the least gravitational potential energy?
d) what can be said about the gpe and mke at positions b and d?
challenge: a+ level.

1. a 2.0kg object is dropped from a height of 30m. after it drops for 2.0 seconds, what is its kinetic energy and what is its potential energy? (assume no air resistance.)

Explanation:

Step1: Find the velocity

Use the formula \(v = v_0+at\). Since the object is dropped, \(v_0 = 0\) and \(a = g= 9.8m/s^2\), \(t = 2.0s\).
\(v=0 + 9.8\times2=19.6m/s\)

Step2: Calculate kinetic energy

Use the formula \(KE=\frac{1}{2}mv^{2}\), where \(m = 2.0kg\) and \(v = 19.6m/s\)
\(KE=\frac{1}{2}\times2\times(19.6)^{2}=384.16J\)

Step3: Calculate the distance fallen

Use the formula \(h=\frac{1}{2}gt^{2}\), \(g = 9.8m/s^2\), \(t = 2.0s\)
\(h=\frac{1}{2}\times9.8\times(2)^{2}=19.6m\)

Step4: Calculate the remaining height

The initial height \(H = 30m\), the remaining height \(h_{remaining}=30 - 19.6=10.4m\)

Step5: Calculate potential energy

Use the formula \(PE=mgh\), \(m = 2.0kg\), \(g = 9.8m/s^2\), \(h = 10.4m\)
\(PE=2\times9.8\times10.4 = 203.84J\)

Answer:

The kinetic energy is \(384.16J\) and the potential energy is \(203.84J\)