Question: A car with a mass of 800 g and velocity of 15 m/s collided with a truck moving in opposite direction with a velocity of 20 m/s, if the momentum is conserved and they both move with a common velocity of 10 m/s, what is the mass of the truck?
Answer:
0.133 kg
Explanation:
Applying the law of conservation of momentum,
Total momentum before collision = Total momentum after collision
mu+m'u' = V(m+m')................... Equation 1
Where m = mass of the car, m' = mass of the truck, u = initial velocity of the car, u' = initial velocity of the truck, V = common velocity.
From the question,
Given: m = 800 g = 0.8 kg, u = 15 m/s, u' = -20 m/s, V = 10 m/s
Substitute these values into equation 2
(0.8*15)+(m'*20) = 10(0.8+m')
Solve for m'
12-20m' = 8+10m'
-20m'-10m' = 8-12
-30m' = -4
m' = -4/-30
m' = 0.133 kg
The answers is
D. The acid creates cracks in the rocks, which
allow air to circulate through the rock,
causing it to weather
To solve this problem it is necessary to apply the concepts given by Malus regarding the Intensity of light.
From the law of Malus intensity can be defined as
Where
Angle From vertical of the axis of the polarizing filter
Intensity of the unpolarized light
The expression for the intensity of the light after passing through the first filter is given by
Replacing we have that
Re-arrange the equation,
Re-arrange to find \theta
The value of the angle from vertical of the axis of the second polarizing filter is equal to 30.2°
Answer:
<h2>8.78 Amps</h2>
Explanation:
Given data:
power rating of the heater P= 1010 W
voltage of the heater V= 115 volts
current taken by the heater I= ?
We can apply the power formula to solve for the current in the heater
i.e P= IV
Making I the current subject of formula we have
I= P/V
Substituting our given data into the expression for I we have
I=1010/115= 8.78 A
<h2 /><h2><em>Hence the current when the unit/heater is operating is 8.78 Amp</em></h2>
Left. Use right hand rule. Have hand wide open. Thumb points in direction of current.(which makes right angle with your index finger) Four fingers in direction of magnetic field and your palm should point in the direction of the force
