Answer:
Decorating. Because mirrors reflect light, they create an illusion of open space by doubling whatever is in a room. ...
Safety. People use mirrors and lenses for safety. ...
Vision. Eye doctors use lenses to correct vision. ...
Magnification and Science. ...
Energy and Affirmation Techniques. ...
Photography. ...
A metal has 4000kg in the volume of 2m3. what is its density
Answer:
2000 kg/m³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question we have
[tex]density = \frac{4000}{2} = 2000 \\ [/tex]
We have the final answer as
2000 kg/m³Hope this helps you
If you drive your 1,000 kg car from sea level up to the mountain, which is 366 m above sea level, how much will you have increased your car's potential energy?(consider : g=10m/s2) *
1 point
a) 366,000 J
b) 3,660,000 J
c) 2.73 J
d) 20.73 J
Answer:
Option B. 3660000 J
Explanation:
At the sea level, we'll assume that the height is 0 m. Hence, the potential energy at the sea level is zero.
Next, we shall determine the potential energy at a height of 366 m above the sea level. This can be obtained as follow:
Mass (m) = 1000 kg
Acceleration due to gravity (g) = 10 m/s²
Height (h) = 366 m
Potential energy (PE) =?
PE = mgh
PE = 1000 × 10 × 366
PE = 3660000 J
From the calculations made above, we can see clearly that the potential energy of the car at a height of 366 m above sea level is 3660000 J.
Hence, the potential energy of the car increases from 0 at the sea level to 3660000 J at 366 m above the sea level.
define relative velocity
What force is required to give an object with mass 50 kg an acceleration of 8 m/s2 O A. 6.25 N O B. 58 N O C, 400 N O D, 250 N
Answer:
C, 400 N
Explanation:
Given parameters:
Mass of object = 50kg
Acceleration = 8m/s²
Unknown:
Amount of force = ?
Solution:
According to Newton's second law of motion;
Force = m a
m is the mass
a is the acceleration
Now insert the parameters and solve;
Force = 50 x 8 = 400N
A cyclist accelerates from a velocity of 10 miles/hour east until reaching a velocity of 20 miles/hour east in 5 seconds. What was the cyclist's acceleration?
Answer:
[tex]a = 0.894\ m/s^2[/tex]
Explanation:
Motion with Constant Acceleration
A body moves with constant acceleration when the speed changes uniformly in time. The equation used to find the final speed vf is
[tex]v_f=v_o+at[/tex]
Where vo is the initial speed, a is the acceleration, and t is the time.
The cyclist has an initial speed of vo=10 miles/hour and ends up at vf=20 miles/hour in t=5 seconds.
Both speeds are given in miles/hour and we must convert it to m/s:
1 mile/hour = 0.44704 m/s
10 mile/hour = 4.47 m/s
20 mile/hour = 8.94 m/s
The acceleration is calculated by solving for a:
[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]
[tex]\displaystyle a=\frac{8.94-4.47}{5}[/tex]
[tex]a = 0.894\ m/s^2[/tex]
A person who normally weighs 700 N is riding in an elevator that is moving upward but slowing down at a steady rate. If this person is standing on a bathroom scale inside the elevator, what would the scale read?
Answer:
The scale will read less than 700 N
Explanation:
Given;
normal weight of the person, W = 700 N
The upward acceleration of the elevator is given by Newton's second law of motion;
F = ma
Also, the weight of the person, W = mg
Net force on the person when the elevator accelerates upward is given as;
R = ma + mg
When the elevator slows down at a steady rate, then net force on the person is given as;
R = mg - ma
R = m(g - a), this net force on the person is also the reading of the scale.
Thus, the scale will read less than 700 N.
Answer: The answer is less than 700 N
Suppose the green car was traveling at 0 miles the white car was traveling at 70 miles at the red car was trailing at 22 miles which car is covering the most distance every second?
Answer:
The white car will cover the most distance every second.
Explanation:
The formula for the uniform speed of an object is given as follows:
[tex]s = vt[/tex]
where,
s = distance covered by the object
v = speed of the object
t = time required
Now, if we assume time to be constant at 1 s. Then the distance covered by each car will be directly proportional to the speed of the car. Hence, the car with the greatest speed will travel the greatest distance in 1 second.
We, have:
Speed of white car > Speed of red car > Speed of green car
Therefore, the white car will cover the most distance every second.