Explanation:
In everyday use and in kinematics, the speed of an object is the magnitude of the rate of change of its position with time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity.
SI unit: m/s, m s−1
s=d/t
Answer:
a) 17.8 m/s
b) 28.3 m
Explanation:
Given:
angle A = 53.0°
sinA = 0.8
cosA = 0.6
width of the river,d = 40.0 m,
the far bank was 15.0 m lower than the top of the ramp h = 15.0 m,
The river itself was 100 m below the ramp H = 100 m,
(a) find speed v
vertical displacement
putting values h=15 m, v=0.8
............. (1)
horizontal displacement d = vcosA×t = 0.6×v ×t
so v×t = d/0.6 = 40/0.6
plug it into (1) and get
solving for t we get
t = 3.734 s
also, v = (40/0.6)/t = 40/(0.6×3.734) = 17.8 m/s
(b) If his speed was only half the value found in (a), where did he land?
v = 17.8/2 = 8.9 m/s
vertical displacement = 
⇒ 
t = 5.30 s
then
d =v×cosA×t = 8.9×0.6×5.30= 28.3 m
Answer:
The mirror in these telescopes will be constructed from many smaller mirrors which will work together.
Explanation:
A telescope is defined as an optical instrument that is used to observe or view the distant objects. A telescope is made up of curved lenses or mirrors or by combining both.
In the context, both the US and the Europeans are planning to make a telescope which is 30 m and 39 m respectively. This could be possible as the mirrors that are used to make these telescope will be made from a many smaller mirrors that will work together as a single large mirror having a very large aperture.
Answer:
x(t) = d*cos ( wt )
w = √(k/m)
Explanation:
Given:-
- The mass of block = m
- The spring constant = k
- The initial displacement = xi = d
Find:-
- The expression for displacement (x) as function of time (t).
Solution:-
- Consider the block as system which is initially displaced with amount (x = d) to left and then released from rest over a frictionless surface and undergoes SHM. There is only one force acting on the block i.e restoring force of the spring F = -kx in opposite direction to the motion.
- We apply the Newton's equation of motion in horizontal direction.
F = ma
-kx = ma
-kx = mx''
mx'' + kx = 0
- Solve the Auxiliary equation for the ODE above:
ms^2 + k = 0
s^2 + (k/m) = 0
s = +/- √(k/m) i = +/- w i
- The complementary solution for complex roots is:
x(t) = [ A*cos ( wt ) + B*sin ( wt ) ]
- The given initial conditions are:
x(0) = d
d = [ A*cos ( 0 ) + B*sin ( 0 ) ]
d = A
x'(0) = 0
x'(t) = -Aw*sin (wt) + Bw*cos(wt)
0 = -Aw*sin (0) + Bw*cos(0)
B = 0
- The required displacement-time relationship for SHM:
x(t) = d*cos ( wt )
w = √(k/m)
Answer:
B) 49 N
Explanation:
m = mass of the wagon = 10 kg
g = acceleration due to gravity acting on the wagon = 9.8 m/s²
W = weight of the wagon
weight of the wagon is given as
W = mg
W = (10) (9.8)
W = 98 N
θ = Angle of the incline = 30°
F = Force required to keep the wagon from sliding
Force required to keep the wagon from sliding is same as the component of weight of the wagon parallel to the surface of the incline
F = W Sinθ
F = 98 Sin30
F = 49 N
