Answer
given,
mass of the ski = 75 Kg
speed of the skier, v = 3 m/s
time = 1.50 min = 90 s
angle of inclination, θ = 40°
distance = s x t
= 3 x 90 = 270 m
a) W = F. d cos θ
W = mg. d cos θ
W = 75 x 9.8 x 270 x cos 40°
W = 152021.52 J
work is done by the ski lift is equal to 152021.52 J
b) Power extended by the ski


P = 1689.13 Watt.
power is expended by the ski lift is equal to 1689.13 W.
Answer:
2.605m
Explanation:
Using the formula for calculating Range (distance travelled in horizontal direction)
Range R = U√2H/g
U is the speed = 4.8m/s
H is the maximum height = ?
g is the acc due to gravity = 9.8m/s²
R = 3.5m
Substitute into the formula and get H
3.5 = 4.8√2H/9.8
3.5/4.8 = √2H/9.8
0.7292 = √2H/9.8
square both sides
0.7292² = 2H/9.8
2H = 0.7292² * 9.8
2H = 5.21
H = 5.21/2
H = 2.605m
Hence the height of the ball from the ground is 2.605m
Pretty much any element(in your case sodium) contain these properties.
Atoms can be an ion, but not all ions are atoms. The difference between an atom and an ion has to do with net electrical charge. An ion is a particle or collection of particles with a net positive or negative charge. ... A stable atom contains the same number of electrons as protons and no net charge
The total power emitted by an object via radiation is:

where:
A is the surface of the object (in our problem,


is the emissivity of the object (in our problem,

)

is the Stefan-Boltzmann constant
T is the absolute temperature of the object, which in our case is

Substituting these values, we find the power emitted by radiation:

So, the correct answer is D.
Answer:
Apply Newton's second law in the moving direction.
Explanation:

Friction force applies in the opposite direction of motion; as a restriction.