Which type of mirror is placed behind the bulb in car headlights?

A firecracker in a coconut blows the coconut into three pieces. Twopieces of equal mass fly off south and west, perpendicular to

loris [4]

Answer:

V = 13m/s

North-East (i.e. 45 degree from North)

Explanation:

This question deals with the idea of momentum.

Since the directions of a compass are fixed, we can take south as horizontal and west as vertical. Since both pieces of coconut are of equal mass, then the resultant of the two pieces would be in between South and West and the third piece would be opposite this direction and be in the North-East (i.e. 45 degree from North) direction

To find the speed of the third piece, we first find the speed on the two pieces of the coconut in terms of $V_{x}$ (horizontal component of velocity) and $V_{y}$ (vertical component of velocity)

We have

$V_{y}$ = Velocity in South direction = 18m/s

$m_{y}$ = Mass of piece in South direction = m

$V_{x}$ = Velocity in West direction = 18m/s

$m_{x}$ = Mass of piece in West direction = m

$V_{ry}$ = Velocity of Third Piece in North direction = unknown

$V_{rx}$ = Velocity of Third Piece in East direction = unknown

$m$ = Mass of third piece = 2m

$mV_{ry} = m_{y} V_{y} \\ 2mV_{ry} = m18\\ V_{ry} = 9$

$mV_{rx} = m_{x} V_{x} \\ 2mV_{rx} = m18\\ V_{rx} = 9$

Since we now know the horizontal and vertical component of the velocity of the third piece of coconut we find the resultant velocity. Since we know the direction is North-East, we can imagine a right angled triangle with base of 9 and height 9 and the hypotenuse equal to the resultant velocity .

We can simply apply the Pythagoras theorem and find the hypotenuse

$Hypotenuse^{2} = Height^{2} + Base^{2} \\ V_{3}^2 = 9^{2} + 9^{2} \\ V = 12.728 m/s$

V = 13m/s

6 0

3 years ago

20. A cannon shoots a ball at 38 m/s at an angle of 30°. Ignore the original height of the cannon and assume level ground.

sergij07 [2.7K]

Answer:
a.3.87s
b.127.36m
c.18.4m

Step by step explanation:
Refer to the diagram

5 0

2 years ago

A particle R moves with a velocity of 6 m/s due East and another particle S moves at 8 m/s due South. What is the magnitude of t

cluponka [151]

Answer:

10

Explanation:

We can look at this problem as a triangle, r is the hypotenuse so if we take the square root of 6^2+8^2 we get 10

6 0

2 years ago

Why does lifting one end of the track lead to constant acceleration?

Rainbow [258]

We put a motion detector at one end of the track and put a cart on the track. ... Next, we put a motorized fan on the cart and let it push the cart down the track. ... This is what I would expect based on the velocity graph, since acceleration equals the slope of the velocity graph, which remainsconstant in time.

7 0

3 years ago

Granite is mostly used in building work places whereas Gneiss is used for making tombstones, flooring, etc. Why do you think so?

lozanna [386]

Answer:

Granite is durable, as it is hard and tough.

Gneiss has resistance to pressure and mechanical impacts

Explanation:

Granite is an igneous rock. It is mostly used in building works and construction because they are very durable. They are hard and tough and they have no internal structures.

Gneiss is used for flooring, ornamental stone, tombstones because of the fact that it shows resistances to pressure and also mechanical impacts.

how they are formed in nature:

In nature, granite is formed from the cooling down of hot molten magma and it's solidification before it reaches the surface of the earth.

In nature, gneiss is as a result of igneous rock or sedimentary rocks metamorphosing. Gneiss and granite are kind of similar. When subjected to great heat, granite becomes gneiss

6 0

2 years ago