Answer:
The object distance is 20cm
Explanation:
Given
Magnification = -1.5
Image distance = 30 cm.
Required
Object Distance
We can calculate the object's distance using magnification formula;
M = -V/U
Where M = Magnification = -1.50
V = Image Distance = 30cm
U = Object Distance
Substitute the above parameters in the formula above.
-1.50 = -30/U
Multiply both sides by -1
-1.50 * -1 = -30/U * -1
1.50 = 30/U
Multiply both sides by U
1.50 * U = 30/U * U
1.50U = 30
Divide through by 1.50
1.50U/1.50 = 30/1.50
U = 30/1.50
U = 20cm
Recall that U represented the object distance.
Hence, the object distance is 20cm
Answer:
u = 23.68 m/s
Explanation:
given,
mass of the car, m = 1900 Kg
Force exerted on the wall, F = 150,000 N
time of contact, t = 0.3 s
final speed of the car = 0 m/s
initial speed of the car = ?
we know,
Impulse is equal to change in momentum
J = m v- mu
J = 1900 x 0 - 1900 x (-u)
J = 1900 u
impulse is also equal to force into time
J = F x t
equating both equation of impulse
1900 u = F x t
1900 u = 150000 x 0.3
1900 u = 45000
u = 23.68 m/s
Speed of the car before collision is equal to 23.68 m/s
According to cuneiform tablets in the ancient world, straight lines cannot cross, and no motion in the world is not relative. Btw...I KNOW!!! GOT MILK???
Answer:
k1 + k2
Explanation:
Spring 1 has spring constant k1
Spring 2 has spring constant k2
After being applied by the same force, it is clearly mentioned that spring are extended by the same amount i.e. extension of spring 1 is equal to extension of spring 2.
x1 = x2
Since the force exerted to each spring might be different, let's assume F1 for spring 1 and F2 for spring 2. Hence the equations of spring constant for both springs are
k1 = F1/x -> F1 =k1*x
k2 = F2/x -> F2 =k2*x
While F = F1 + F2
Substitute equation of F1 and F2 into the equation of sum of forces
F = F1 + F2
F = k1*x + k2*x
= x(k1 + k2)
Note that this is applicable because both spring have the same extension of x (I repeat, EXTENTION, not length of the spring)
Considering the general equation of spring forces (Hooke's Law) F = kx,
The effective spring constant for the system is k1 + k2
Answer:
Ans is (B) driving a rock from a building
