Answer:
4 seconds
Explanation:
Given:
v₀ = 0 m/s
v = 20 m/s
a = 5 m/s²
Find: t
v = at + v₀
20 m/s = (5 m/s²) t + 0 m/s
t = 4 s
Momentum should be conserved. The momentum of both
objects must balance with their initial and final momentum.
Let m1 and v1 be the mass and velocity of the
bowling ball
And m2 and v2 be the mass and velocity of the
bowling pin
(m1v1)i + (m2v2)i = (m1v1)f + (m2v2)f
30 kg m/s + (1.5 kg)(0 m/s) = 13kg m/s + 1.5v2f
V2f = 11.33 m/s
<span>So the momentum = 1.5 kg(11.33 m/s) = 17 kg m/s</span>
Answer:

Explanation:
given,
refractive index of lens, n = 1.70
Radius of curvature of front surface. R₁ = 20 cm
Radius of curvature of the back surface, R₂ = 30 cm
focal length= ?

R₁ = +20 cm
R₂ = -30 cm
n = 1.70




the focal length of the lens is equal to 17.15 cm
Answer:
D. a person pulling a sled.
Explanation:
contact force only occurs when something directly comes in contact with another object.
a. is wrong because that is called magnetic force.
b. gravitational force
c. is an electrical force