Answer:
1.09 km, 3 km
Explanation:
displacement, d = 3.20 km at 20° North of east
A vector quantity has two components one along the x axis and the other is along Y axis. the component along X axis is called the horizontal component and it is due east.
The component along y axis is called vertical component and it is due North.
Displacement due North, dy = 3.20 Sin 20° = 1.09 km
Displacement due east, dx = 3.20 Cos 20° = 3 km
Let the initial velocity be u = 23 m/s
Let the final velocity be v.
Vehicle stops finally, therefore v = 0 m/s
Here during the braking, vehicle decelerates with constant acceleration, thus the change in velocity is linear from initial velocity to final velocity.
for the Given condition:
Write the expression for the average speed
Substitute the values in the above expression.
Hence, the average speed during braking is 11.5 m/s
Force of gravity on an object is the weight of the object and is given by mass times accerelation due to gravity. The accerelation due to gravity is the accerelation of an object in free fall and is given by 9.8m/s^2. Given that the force of gravity acting on a child's mass on earth is 490 newtns, i.e. F = mg which means that 490 newtons = 9.8 times mass. Therefore, mass of the child is 490 / 9.8 = 50 kg.
Answer: R = 28 degree
Explanation:
The given parameters are:
Refractive index n = 1.52
Incident angle I = 45 degree
According to Snell law,
Sin I/Sin R = n
Where
I = angle of incidence
R = angle of refraction
n = refractive index
Substitute all the parameters into the formula
1.52 = sin 45/ sin R
Make sinR the subject of formula
Sin R = sin 45/1.52
Sin R = 0.46520
R = sin^-1(0.46520)
R = 27.72 degree
Therefore, the angle of refraction will be 28 degrees approximately.
Answer:
The amount of heat flows per second in given aluminium bar is 3.066 .
Explanation:
We know that , amount of heat flowing per second is given by
Where A = area =
K = Thermal conductivity =
L = Length =
Upon substituting these values in above equation we get ,
Heat flowing per second =