Answer:
1. The car which is twice as massive as the other will have twice potential energy.
Explanation:
The potential energy of an object is given by:
where
m is the mass of the object
g is the gravitational acceleration
h is the height of the object measured to some reference level
In this problem, we have two cars at same elevation (= same h in the formula) but one car has twice the mass of the second car. Calling m the mass of one car and 2m the mass of the second car, we have:
- Potential energy of the first car:
- potential energy of the second car:
So, the car which is twice as massive as the other will have twice potential energy.
Answer:
0.84 Ω
Explanation:
r = mean radius of the turn = 6.5 mm
n = number of turns of copper wire = 150
Total length of wire containing all the turns is given as
L = 2πnr
L = 2 (3.14)(150) (6.5)
L = 6123 mm
L = 6.123 m
d = diameter of the wire = 0.4 mm = 0.4 x 10⁻³ m
Area of cross-section of the wire is given as
A = (0.25) πd²
A = (0.25) (3.14) (0.4 x 10⁻³)²
A = 1.256 x 10⁻⁷ m²
ρ = resistivity of copper = 1.72 x 10⁻⁸ Ω-m
Resistance of the coil is given as
R = 0.84 Ω
Answer:
The magnitude of change in the ball's momentum is 4 kgm/s
Explanation:
Given;
mass of the ball, m = 0.2 kg
initial velocity of the ball, u = 40 m/s
final velocity experienced by the ball, v = 60 m/s
Therefore, the change in momentum of the ball is given as final momentum minus initial mometum;
ΔP = mv - mu
ΔP = m(v-u)
ΔP = 0.2 (60 - 40)
ΔP = 4 kgm/s
Therefore, the magnitude of change in the ball's momentum is 4 kgm/s
