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
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 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
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
Uses of lens and mirror in daily life
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. ...
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.