Answer:
Explanation:
mass of car, m = 1000 kg
initial velocity, u = 20 m/s
final velocity, v = 0 m/s
distance, s = 120 m
Let a be the acceleration of motion
use third equation of motion
v² = u² + 2 as
0 = 20 x 20 + 2 x a x 120
a = - 1.67 m/s²
Let F be the force
Force, F mass x acceleration
F = - 1000 x 1.67
F = - 1666.67 N
The direction of force is towards south and the magnitude of force is 1666.67 N.
Answer:
a. 
b. 
Explanation:
The inertia can be find using
a.





now to find the torsion constant can use knowing the period of the balance
b.
T=0.5 s

Solve to K'


P = m * v
v = {3i - 4j} = square root (3^2 + 4^2) = 5
P = 20 * 5
P = 100 kg m/s
1000 kcal because you only get 10% of the energy of the thing you eat
Following statements are true
(i) The leather jacket has a lower tendency to attract electrons than sweater.
When the sweater and the leather jacket are in contact with each other, the leather jacket loses electrons and thus becomes positively charged. the electrons are gained by the sweater and it becomes negatively charges.
The opposite charge attract. so the sweater ( negatively charged) will attract protons ( positively charged) . The leather jacket ( positively charged) will attract the electrons ( negatively charged).