Answer:
1.4 m/s/s (2.s.f)
Explanation:
The formula for centripetal acceleration is:
, where v is velocity and r is the radius.
In the question we are given the information that the car has a mass of 1300kg, a velocity of 2.5m/s, and a turn radius of 8.5m which are all the values we need. Therefore we can simply substitute in the values to solve the question:

Therefore the centripetal acceleration of the car is 1.4m/s/s. (2.s.f)
Hope this helped!
A globe sitting on the desk can't demonstrate the speed of axial rotation
or the speed of orbital revolution.
Answer:
8.60 g/cm³
Explanation:
In the lattice structure of iron, there are two atoms per unit cell. So:
where
an and A is the atomic mass of iron.
Therefore:

This implies that:

= 
Assuming that there is no phase change gives:

= 8.60 g/m³
Answer:
Explanation:
The energy of a photon is given by the equation
, where h is the <em>Planck constant</em> and f the frequency of the photon. Thus, N photons of frequency f will give an energy of
.
We also know that frequency and wavelength are related by
, so we have
, where c is the <em>speed of light</em>.
We will want the number of photons, so we can write

We need to know then how much energy do we have to calculate N. The equation of power is
, so for the power we have and considering 1 second we can calculate the total energy, and then only consider the 4% of it which will produce light, or better said, the N photons, which means it will be
.
Putting this paragraph in equations:
.
And then we can substitute everything in our equation for number of photons, in S.I. and getting the values of constants from tables:

Answer:4kg
Explanation:
acceleration due to gravity(g)=10m/s^2
Weight(w)=40N
Weight=mass x g
40=mass x 10
Divide both sides by 10
Mass =40/10
Mass=4kg