Answer:
distance between the dime and the mirror, u = 0.30 m
Given:
Radius of curvature, r = 0.40 m
magnification, m = - 2 (since,inverted image)
Solution:
Focal length is half the radius of curvature, f =
f =
Now,
m = -
- 2 = -
= 2 (2)
Now, by lens maker formula:
v = (3)
From eqn (2):
v = 2u
put v = 2u in eqn (3):
2u =
2 =
2(u - 0.20) = 0.20
u = 0.30 m
<span>The rate of change in velocity is acceleration.</span>
Answer:
v₁ = -0.8087 m / s
Explanation:
To solve this problem we can use the conservation of momentum, for this we define a system formed by the man, the skateboard and the brick, therefore the force during the separation is internal and the momentum is conserved
Initial instant. When they are united
p₀ = 0
Final moment. After throwing the brick
= (m_man + m_skate) v1 + m_brick v2
the moment is preserved
p₀ = p_{f}
0 = (m_man + m_skate) v₁ + m_brick v₂
v₁ = -
the negative sign indicates that the two speeds are in the opposite direction
let's calculate
v₁ = -
v₁ = -0.8087 m / s
Newton's 2nd law of motion: Force = (mass) x (acceleration)
Divide each side by (mass) : Acceleration = (force) / (mass)
Acceleration of the truck = (4,200 N) / (2,000 kg) = 2.1 m/s²