Answer:
Explanation:
We shall apply conservation of mechanical energy .
initial kinetic energy = 1/2 m v²
= .5 x m x 12 x 12
= 72 m
This energy will be spent to store potential energy . if h be the height attained
potential energy = mgh , h is vertical height attined by block
= mg l sin20 where l is length up the inclined plane
for conservation of mechanical energy
initial kinetic energy = potential energy
72 m = mg l sin20
l = 72 / g sin20
= 21.5 m
deceleration on inclined plane = g sin20
= 3.35 m /s²
v = u - at
t = v - u / a
= (12 - 0) / 3.35
= 3.58 s
it will take the same time to come back . total time taken to reach original point = 2 x 3.58
= 7.16 s
Answer:
f = 347.08 N
Explanation:
The frictional force exerted by the floor on the refrigerator is given as follows:
where,
f = frictional force = ?
μ = coefficient of static friction = 0.58
W = Weight of refrigerator = mg
m = mass of refrigerator = 61 kg
g = acceleration due to gravity = 9.81 m/s²
Therefore,
<u>f = 347.08 N</u>
Answer: 2.13 × 10⁻⁷ N
Explanation:
Gravitational force exists between any two bodies having mass.
Force of gravity is given by:
It is given that, mass of newborn baby is M = 2.50 kg
Mass of the doctor, m = 80.0 kg
Distance between the two, r = 0.250 m
Gravitational constant, G = 6.67 × 10⁻¹¹ N m²/kg²
⇒F = (6.67 × 10⁻¹¹ N m²/kg² × 2.50 kg × 80.0 kg )÷ (0.250 m)² = 2.13 × 10⁻⁷ N
Thus, the force of gravity between new born baby and doctor is 2.13 × 10⁻⁷ N.
Any two objects in the universe attract each other. Gravity is the force exerted by earth on you (you exert the same force on earth) but due to the fact that earth has a huge mass compared to yours, you will be attracted to earth only by a small gravitational force.
<span>I think that the coefficient of cubical expansion of a substance depends on THE CHANGE IN VOLUME.
Cubical expansion, also known as, volumetric expansion has the following formula:
</span>Δ V = β V₁ ΔT
V₁ = initial volume of the body
ΔT = change in temperature of the body
β = coefficient of volumetric expansion.
β is defined as the <span>increase in volume per unit original volume per Kelvin rise in temperature.
</span>
With the above definition, it is safe to assume that the <span>coefficient of cubical expansion of a substance depends on the change in volume, which also changes in response to the change in temperature. </span>
