Answer:
Detailed explanation:
Density of water=1000kg/m³
Hence mass of water displaced is:
m=d×v
=1000kg/m³×(4.3×10^-3)m³ (volume of water displaced converted to L)
=4.3 kg of water
Hence, mass of football is also 4.3 kg(Archimedes principle)
Thus density of football
=mass÷volume
substitute the mass and volume and solve.
hope this helps
Answer:
360J
Explanation:
In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest.
De broglie wavelength,
, where h is the Planck's constant, m is the mass and v is the velocity.

Mass of hydrogen atom, 
v = 440 m/s
Substituting
Wavelength 

So the de broglie wavelength (in picometers) of a hydrogen atom traveling at 440 m/s is 902 pm
Answer:
20.6 N
Explanation:
Friction equals normal force times coefficient of friction.
F = Fn μ
On level ground, normal force equal weight.
Fn = W
Therefore:
F = W μ
F = (685 N) (0.0300)
F = 20.6 N
Answer:
a) 
b) 
Explanation:
Given:
String vibrates transversely fourth dynamic, thus n = 4
mass of the string, m = 13.7 g = 13.7 × 10⁻¹³ kg
Tension in the string, T = 8.39 N
Length of the string, L = 1.87 m
a) we know

where,
= wavelength
on substituting the values, we get

or

b) Speed of the wave (v) in the string is given as:

also,

equating both the formula for 'v' we get,

on substituting the values, we get

or

or
