Answer:
Explanation:
Actual weight, Wo = 5 N
Apparent weight, W = 4.5 N
density of water = 1 g/cm^3 = 1000 kg/m^3
density of gold, = 19.32 g/cm^3 = 19.32 x 1000 kg/m^3
Buoyant force = Actual weight - Apparent weight
Volume x density of water x g = 5 - 4.5
V x 1000 x 9.8 = 0.5
V = 5.1 x 10^-6 m^3
Weight of gold = Volume of gold x density of gold x gravity
W' = 5.1 x 10^-6 x 19.32 x 1000 x 9.8 = 0.966 N
As W' is less than W so, it is not pure gold.
Answer:

Explanation:
By Einstein's Equation of photoelectric effect we know that

here we know that
= energy of the photons incident on the metal
= minimum energy required to remove photons from metal
= kinetic energy of the electrons ejected out of the plate
now we know that it requires 351 nm wavelength of photons to just eject out the electrons
so we can say

here we know that

now we have

now by energy equation above when photon of 303 nm incident on the surface





Answer:
The force required to begin to lift the pole from the end 'A' is 240 N
Explanation:
The given parameters for the pole AB are;
The length of the pole, l = 10.0 m
The weight of the pole, W = 600 N ↓
The distance of the center of gravity of the pole from the side 'A' = 4.0 m
Let '
' represent the force required to begin to lift the pole from the end 'A' and let a force applied in the upwards direction be positive
For equilibrium, the sum of moment about the point 'B' = 0, therefore, taking moment about 'B', we have
× 10.0 m - W × 4.0 m = 0
∴
× 10.0 m = W × 4.0 m = 600 N × 4.0 m
× 10.0 m = 600 N × 4.0 m
∴
= 600 N × 4.0 m/(10.0 m) = 240 N
The force required to begin to lift the pole from the end 'A',
= 240 N.
Distance is 50 km
Displacement is 10 km
<u>Explanation:</u>
Given:
Distance toward south, x = 25 km
Distance towards west, y = 10 km
Distance towards north, z = 15 km
(a) Total distance, D = ?
Total distance, D = x + y + z
D = 25 + 10 + 15
D = 50km
(b) Displacement, d = ?
Displacement = final position - initial position
= 10 - 0 km
= 10km
Answer:
four seconds
Explanation:
A player who catches the ball and is being closely guarded may hold the ball for four seconds, then dribble the ball for four seconds, then hold the ball for another four seconds, then pass, will not be in violation of this rule.