Answer:
The correct answer is "64 J".
Explanation:
The given values are:
Mass,
m = 52 kg
Velocity,
v = 6 m/s
Mechanical energy,
= 1000 J
Now,
The gravitational potential energy will be:
⇒ [tex]P.E=1000-\frac{1}{2}mv^2[/tex]
[tex]=1000-\frac{1}{2}\times 52\times (6)^2[/tex]
[tex]=1000-26\times 36[/tex]
[tex]=1000-936[/tex]
[tex]=64 \ J[/tex]
with respect to air the refractive index of ice is 1.31 and that of rock salt is 1.54 calculate the refractive index of rock salt with respect to ice
Answer:
1.17
Explanation:
Given that,
The refractive index of ice wrt air = 1.31
The refractive index of rock salt wrt air = 1.54
We need to find the refractive index of rock salt with respect to ice.
We know that,
refractive index = (speed of light in air or vaccum)/( speed of light in that medium)
So,
The speed of light in ice = c/(1.31)
The speed of light in rock salt = c/(1.54)
So, the refractive index of rock salt with respect to ice is :
[tex]\mu=\dfrac{1.54}{1.31}\\\\=1.17[/tex]
So, the required refractive index of rock salt wrt ice is 1.17.
when is the acceleration of body is positive negative and zero?
Answer:
【 In vector form , if angle between velocity vector and acceleration vector is less than 90° and greater than 0° then it is positive acceleration and if it is less than 180° and greater than 90° then it is negative acceleration. If there is no acceleration vector then it is called zero acceleration. 】
At the local grocery store, you push a 14.5-kg shopping cart. You stop for a moment to add a bag of dog food to your cart. With a force of 12.0 N you now accelerate the cart from rest through a distance of 2.29 m in 3.00 s. What was the mass of the dog food?
Answer:
The mass of the dog food added is 9.03 kg
Explanation:
Given;
mass of the shopping cart, m₁ = 14.5 kg
let the mass of the bag added = m₂
the force applied, F = 12 N
initial velocity of the cart-bag system, u = 0
distance traveled by the system, d = 2.29 m
time of motion of the system, t = 3.0 s
The acceleration of the system is calculated as;
[tex]d = ut + \frac{1}{2} at^2\\\\2.29 = 0 + (\frac{1}{2} \times 3^2)a\\\\2.29 = 4.5 a\\\\a = \frac{2.29}{4.5} \\\\a = 0.51 \ m/s^2[/tex]
The total mass of the system (M) is calculated as follows;
F = Ma
M = F/a
M = (12)/(0.51)
M = 23.53 kg
The mass of the dog food added is calculated as;
m₂ = M - m₁
m₂ = 23.53 kg - 14.5 kg
m₂ = 9.03 kg
Ball X has a mass of 8kg and is moving toward ball Y (which is sitting still) at 2m/s. After they collide, ball X is
sitting still. How fast is ball Y moving after the collision if it has a mass of 4kg?
Answer:
v = 4 m/s
Explanation:
Given :
Ball X :
Mass, m1 = 8kg ;
Initial Velocity, u1 = 2 m/s
Final velocity, v1 = 0
Ball Y:
Mass, m2 = 4kg ;
Initial Velocity, u2 = 0 m/s
Final velocity, v2 = v
(m1u1 + m2u2) = (m2v2 + m1v1)
(8*2 + 4*0) = (4*v + 4*0)
16 + 0 = 4v + 0
16 = 4v
v = 16 / 4
v = 4 m/s
Answer:
Explanation:
This is the Law of Momentum Conservation which for us looks like this:
[tex][m_xv_x+m_yv_y]_b=[m_xv_x+m_yv_y]_a[/tex] and that should look familiar to you if this is what you are doing in physics. Filling in our particular info:
[(8.0 × 2.0)+ (4.0 × 0.0)] = [(8.0 × 0.0) + (4.0v)] and
16 + 0 = 0 + 4.0v and
16 = 4.0v so
v = 4.0 in the direction of ball X
A HIGH SPEED TRAIN IS 180M LONG AND IT IS TRAVELLING AT 50M/S.HOW LONG WILL IT TAKE TO PASS A PERSON STANDING AT A LEVEL CROSSING?
B-HOW LONG WILL IT TAKE TO PASS COMPLETELY THROUGH A STATION WHOSE PLATFORMS ARE 220M IN LENGTH?
Answer:
a. Time = 3.6 seconds
b. Time = 4.4 seconds
Explanation:
Given the following data;
Distance = 180 m
Speed = 50 m/s
a. To find the time;
Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.
Mathematically, speed is given by the formula;
[tex]Speed = \frac{distance}{time}[/tex]
Making time the subject of formula, we have;
[tex]Time = \frac{distance}{speed}[/tex]
Substituting into the equation, we have;
[tex]Time = \frac{180}{50}[/tex]
Time = 3.6 seconds
b. Distance = 220 meters
Speed = 50 m/s
To find the time;
[tex]Time = \frac{distance}{speed}[/tex]
Substituting into the equation, we have;
[tex]Time = \frac{220}{50}[/tex]
Time = 4.4 seconds
"" damped force equation ""
Answer:
In many vibrating systems the frictional force Ff can be modeled as being proportional to the velocity v of the object: Ff = −cv, where c is called the viscous damping coefficient.
Which type of wave causes particles of matter to vibrate in a direction
perpendicular to the direction of its motion?
O A. Sound
B. Transverse
C. Longitudinal
D. Compression
Answer:
C.) Longitudinal
Select the correct answer.
Which quantity is a vector quantity?
ОА. .
acceleration
OB.
mass
OC.
speed
O D.
volume
Reset
Next
Answer:
acceleration is the vector quantity because it depends on particular direction and has magnitude
Which energy store is increased when an object is heated?
Answer:
Kinetic Energy
Explanation:
