Explanation:
Given that,
Force acting on the child, F = 310 N
Length of the ropes, d = 2.1 m
We need to find the gravitational potential energy of the child–Earth system relative to the child's lowest position when the ropes are horizontal. The potential energy is simply given by :

Hence, this is the required solution.
Answer:
a) = 3.94 m
b) = 3.15 m
Explanation:
Given
Mass of the block, m = 242 g
Force constant, k = 1.62 kN/m
Compression of the spring, x = 10 cm
Angle of inclination = 60°
a) if we equate the energy at the bottom of the ramp to the energy at a distance d up the ramp, we have
1/2kx² = mgh where, h = dsinΦ
1/2kx² = mgdsinΦ
1/2 * 1.62*10^3 * 0.1² = 0.242 * 9.8 * dsin 60
1/2 * 16.2 = 2.3716 * d sin 60
d sin 60 = 8.1 / 2.3716
0.866 d = 3.415
d = 3.415 / 0.866
d = 3.94 m
b) net force on the block = mgd sin 60 + µ mgd cos 60
8.1 = d[mg sin 60 + µ mg cos 60]
8.1 = d [0.242 * 9.8 * 0.866 + 0.44 * 0.242 * 9.8 * 0.5]
8.1 = d (2.05 + 0.52)
8.1 = 2.57 d
d = 8.1 / 2.57
d = 3.15 m
I strongly disagree. There are many other planets in our solar system that have gravity on them. The statement is false. I hope this helps.
So we want to know how does the speed of a shallow water wave varies. If the wavelength is large enough in comparison to the depth of the water, meaning the wavelength is 20 times longer than the depth of water, the speed of a shallow water wave is the square root of gravity times water depth or: v=√(g*d), where v is speed of the wave, g=9.81 m/s^2 and d is water depth.
Explanation:
It is given that, a batter hits a pop-up to a fielder 93 m away, range of the projectile, R = 93 m
The ball remains in the air for 5.4 s, the time of flight is 5.4 s
Time of flight : 

Maximum height of the projectile : 
We need to find H.
So,

So, it will rise to a height of 35.72 m.