Answer:
3.6 x 10⁶ Pa
Explanation:
A = Area of the heel = 1.50 cm² = 1.50 x 10⁻⁴ m²
m = mass of the woman = 55.0 kg
g = acceleration due to gravity = 9.8 m/s²
Force of gravity on the heel is given as
F = mg
Inserting the values
F = (55) (9.8)
F = 539 N
Pressure exerted on the floor is given as
P = 3.6 x 10⁶ Pa
Answer:
17 °C
Explanation:
From specific Heat capacity.
Q = cm(t₂-t₁)................. Equation 1
Where Q = Heat absorb by the metal block, c = specific heat capacity of the metal block, m = mass of the metal block, t₂ = final temperature, t₁ = Initial temperature.
make t₁ the subject of the equation
t₁ = t₂-(Q/cm)............... Equation 2
Given: t₂ = 22 °C, Q = 5000 J, m = 4 kg, c = 250 J/kg.°c
Substitute into equation 2
t₁ = 22-[5000/(4×250)
t₁ = 22-(5000/1000)
t₁ = 22-5
t₁ = 17 °C
Answer: The height above the release point is 2.96 meters.
Explanation:
The acceleration of the ball is the gravitational acceleration in the y axis.
A = (0, -9.8m/s^)
For the velocity we can integrate over time and get:
V(t) = (9.20m/s*cos(69°), -9.8m/s^2*t + 9.20m/s^2*sin(69°))
for the position we can integrate it again over time, but this time we do not have any integration constant because the initial position of the ball will be (0,0)
P(t) = (9.20*cos(69°)*t, -4.9m/s^2*t^2 + 9.20m/s^2*sin(69°)*t)
now, the time at wich the horizontal displacement is 4.22 m will be:
4.22m = 9.20*cos(69°)*t
t = (4.22/ 9.20*cos(69°)) = 1.28s
Now we evaluate the y-position in this time:
h = -4.9m/s^2*(1.28s)^2 + 9.20m/s^2*sin(69°)*1.28s = 2.96m
The height above the release point is 2.96 meters.
<u>Answer:</u>
Submarines use a device called Periscope that uses the concept of multiple reflections and help us see objects above the water surface.
<u>Explanation:</u>
When a light ray falls on a reflecting surface like a mirror, it gets reflected. In multiple reflections, the incident light ray is made to reflect multiple times by arranging the reflecting surfaces in different ways.
In submarines, we use Periscope, which is a long tube like structure. The long tube is bent at ends. It uses two simple mirrors which are placed parallel to each other at an angle of 45 degrees. The light from one mirror gets reflected to the other mirror, thus causing a multiple reflection.
