We use the following expression
T = 2*pi *sqrt(l/g)
Where T is the period of the pendulum
l is the length of the pendulum
and g the acceleration of gravity
We solve for l
l = [T/2*pi]² *g = [30s/2*pi]²* 9.8 [m/s²] = 223.413 m
The tower would need to be at least 223.413 m high
D. 51 N. The minimum applied force that will cause the television slide is 51 N.
In order to solve this problem we have to use the force of static friction equation Fs = μs*n, where μs is the coefficient of static friction, and n is the normal force m*g.
With μs = 0.35, and n = 15kg*9.8m/s² = 147 N
Fs = (0.35)(147 N)
Fs = 51.45 N
Fs ≅ 51 N
The second one is correct not sure about the first one sorry
Answer: A
Explanation: How large a parachute is (in other words, the parachute's surface area) affects its air resistance, or drag force. ... In the case of these parachutes, the drag force is opposite to the force of gravity, so the drag force slows the parachutes down as they fall.