Answer:
F = GMm / r²
from Newton's law of gravitational attraction
If you transfer equal amounts of geat to 1kg of water and 1kg of cooper, the temperature of the cooper will change more . . . it'll get more degrees warmer than the water will.
That's because the specific geat of water is greater than the specific geat of cooper.
(This just means it takes more geat to warm some mass of water by some amount than it takes to warm the same mass of cooper by the same amount.)
Answer:
a

b

Explanation:
From the question we are told that
The wavelength is 
The energy is 
This energy is mathematically represented as

Where c is the speed of light with a value 
h is the Planck's constant with the value 
n is the number of pulses
So

substituting values


Given that the pulses where emitted 20 times in one second then the period of the pulse is


Hence the average power of photons in one 80-mJ pulse during 1 s is mathematically represented as

substituting values


Answer:
75 Newtons.
Explanation:
From Newton's second law of motion,
F = m(v-u)/t................... Equation 1
Where F = force exerted by the ball on the bat, m = mass of the ball, v = final velocity of the ball, u = initial velocity of the ball, t = time
Given: m = 0.6 kilogram, u = 0 meter per seconds (at rest), v = 25 meters per seconds, t = 0.2 seconds.
Substitute into equation 1
F = 0.6(25-0)/0.2
F = 3(25)
F = 75 Newton.
Hence the magnitude of the average force exerted by the ball on the bat = 75 Newtons.