Answer:
Aluminium, Nickel, Cobalt and Iron plus varying levels of Copper, Titanium and Niobium.
MAGNETIC: Alni, Alcomax, Hycomax, Columax, and Ticonal.
In order to find the efficiency first we will find the Change in Potential energy of the small stone that robot picked up
First we will find the mass of the stone
As it is given that stone is spherical in shape so first we will find its volume



Now it is given that it's specific gravity is 10.8
So density of rock is

mass of the stone will be



now change in potential energy is given as

here
g = gravity on planet = 0.278 m/s^2
H = height lifted upwards = 15 cm


Now energy supplied by internal circuit of robot is given by

V = voltage supplied = 10 V
i = current = 1.83 mA
t = time = 12 s


Now efficiency is defined as the ratio of output work with given amount of energy used


so efficiency will be 23 %
Answer:17.08 s
Explanation:
Given
distance between First and second Runner is 45.6 m
speed of first runner
=3.1 m/s
speed of second runner
=4.65 m/s
Distance between first runner and finish line is 250 m
Second runner need to run a distance of 250+45.6=295.6 m
Time required by second runner 
time required by first runner to reach finish line
Thus second runner reach the finish line 80.64-63.56=17.08 s earlier
Given:
v = 50.0 m/s, the launch velocity
θ = 36.9°, the launch angle above the horizontal
Assume g = 9.8 m/s² and ignore air resistance.
The vertical component of the launch velocity is
Vy = (50 m/s)*sin(50°) = 30.02 m/s
The time, t, to reach maximum height is given by
(30.02 m/s) - (9.8 m/s²)*(t s) = 0
t = 3.0634 s
The time fo flight is 2*t = 6.1268 s
The horizontal velocity is
u = (50 m/s)cos(36.9°) = 39.9842 m/s
The horizontal distance traveled at time t is given in the table below.
Answer:
t, s x, m
------ --------
0 0
1 39.98
2 79.79
3 112.68
4 159.58
5 199.47
6 239.37