Answer:
A
Step-by-step explanation:
Mechanical energy (ME) is Kinetic energy + potential energy
Where
Kinetic Energy (KE) = 1/2 * m * v^2
where m is the mass (in kg) and v is the speed of the object (in m/s)
and
Potential Energy (PE) = m*g*h
Where m is the mass (in kg) and g is the gravitational constant (9.81 m/s) and h is the height (in meters)
Hence
ME = KE + PE (note the pendulum DOES NOT have any speed, so v = 0, and thus KE = 0)
So,

Hence, Mechanical Energy is 9.8 Joules (rounded to 1 decimal place). Correct answer is A.
Can we see the cones please
Answer:
a: 42%
b: 68%
Step-by-step explanation:
What are your options for the questions.
The length = 6W + 7. 2L + 2W = 70. This is a system of equations. To get L by itself in the second problem, -2W from both sides to get 2L = 70 - 2W. Divide by 2 to get L = 35 - W. Now put them together. 6W +7 = 35 - W. Add W to both sides to get 7W + 7 = 35. Subtract 7 from both sides to get 7W = 28. Divide 7 to both sides to get W = 4. Now replace W with 4. 6(4) + 7 = L. 24 + 7 = 31. The length is 31. To check, do the second equation. 2(31) + 2(4) = 62 + 8 = 70. Your answer is 31.